diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index 6afe2da0..b6d9824a 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -26,7 +26,7 @@ jobs:
           # Don't use macOS for now, it is currently unstable, otherwise slow. -- 2022-04-19, amo
           # 'macos-latest',
         ]
-        python-version: ['2.7']
+        python-version: ['3.8']
 
     defaults:
       run:
@@ -103,7 +103,7 @@ jobs:
     - name: Setup Python
       uses: actions/setup-python@v4
       with:
-        python-version: '2.7'
+        python-version: '3.8'
         architecture: 'x64'
         cache: 'pip'
         cache-dependency-path: 'requirements-docs.txt'
diff --git a/CHANGES.rst b/CHANGES.rst
index 349304fb..06c14c37 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -142,6 +142,8 @@ Development
 - [mw] Improve settings for having per-vendor OPS credentials
 - [ui] More flexbox for header layout
 - [ui] Improve comment editing usability
+- [mw] No need to manually encode form fields with "mechanize" anymore.
+  Thanks, `Kovid <https://github.com/kovidgoyal>`_!
 
 
 2019-05-08 0.165.0
diff --git a/Makefile b/Makefile
index 7950e4e1..821b7e77 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 #VERSION := $(shell cat patzilla/version.py | awk '{ print $$3 }' | tr -d "'")
 #$(error VERSION=$(VERSION))
 
-$(eval venvpath     := .venv2)
+$(eval venvpath     := .venv3)
 $(eval pip          := $(venvpath)/bin/pip)
 $(eval twine        := $(venvpath)/bin/twine)
 $(eval python       := $(venvpath)/bin/python)
@@ -9,10 +9,8 @@ $(eval pserve       := $(venvpath)/bin/pserve)
 $(eval pytest       := $(venvpath)/bin/pytest)
 $(eval bumpversion  := $(venvpath)/bin/bumpversion)
 $(eval fab          := $(venvpath)/bin/fab)
-
-$(eval venv3path     := .venv)
-$(eval yarn          := $(venv3path)/bin/yarn)
-$(eval npx           := $(venv3path)/bin/npx)
+$(eval yarn         := $(venvpath)/bin/yarn)
+$(eval npx          := $(venvpath)/bin/npx)
 
 
 setup: setup-py
@@ -65,7 +63,7 @@ upload-pypi:
 
 # Setup Python virtualenv.
 setup-virtualenv:
-	@test -e $(python) || virtualenv --python=python2 $(venvpath)
+	@test -e $(python) || virtualenv --python=python3 $(venvpath)
 
 setup-py: setup-virtualenv
 	$(pip) install --editable=.[test]
diff --git a/docs/conf.py b/docs/conf.py
index 3a19a2d2..5569cd62 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -49,18 +49,18 @@
 master_doc = 'index'
 
 # General information about the project.
-project = u'PatZilla'
-copyright = u'2013-2022, The PatZilla authors'
-author = u'The PatZilla authors'
+project = 'PatZilla'
+copyright = '2013-2023, The PatZilla authors'
+author = 'The PatZilla authors'
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
 # built documents.
 #
 # The short X.Y version.
-version = u'0.169.3'
+version = '0.169.3'
 # The full version, including alpha/beta/rc tags.
-release = u'0.169.3'
+release = '0.169.3'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
@@ -145,8 +145,8 @@
 # (source start file, target name, title,
 #  author, documentclass [howto, manual, or own class]).
 latex_documents = [
-    (master_doc, 'PatZilla.tex', u'PatZilla Documentation',
-     u'The PatZilla authors', 'manual'),
+    (master_doc, 'PatZilla.tex', 'PatZilla Documentation',
+     'The PatZilla authors', 'manual'),
 ]
 
 
@@ -155,7 +155,7 @@
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
 man_pages = [
-    (master_doc, 'patzilla', u'PatZilla Documentation',
+    (master_doc, 'patzilla', 'PatZilla Documentation',
      [author], 1)
 ]
 
@@ -166,7 +166,7 @@
 # (source start file, target name, title, author,
 #  dir menu entry, description, category)
 texinfo_documents = [
-    (master_doc, 'PatZilla', u'PatZilla Documentation',
+    (master_doc, 'PatZilla', 'PatZilla Documentation',
      author, 'PatZilla', 'One line description of project.',
      'Miscellaneous'),
 ]
diff --git a/fabfile.py b/fabfile.py
index d0c5d1f5..377b1400 100644
--- a/fabfile.py
+++ b/fabfile.py
@@ -34,7 +34,7 @@ def install(version, target):
     if not version:
         version = pkg_version
 
-    print 'Installing package {0}, version {1} to target {2}.'.format(*map(yellow, [pkg_name, version, target]))
+    print('Installing package {0}, version {1} to target {2}.'.format(*list(map(yellow, [pkg_name, version, target]))))
     if env.confirm:
         response = ask('Proceed (y/n)? ', ('y', 'n'))
     else:
@@ -72,7 +72,7 @@ def install(version, target):
         restart_service(target)
 
     else:
-        print yellow('Skipped package install due to user request.')
+        print(yellow('Skipped package install due to user request.'))
 
 def setup_package(package, virtualenv, options=''):
     #--index-url=http://c.pypi.python.org/simple
@@ -100,7 +100,7 @@ def restart_service(target):
     if uwsgi_name:
         run('service uwsgi reload %s' % uwsgi_name)
     else:
-        print(red('WARNING: Could not restart service "%s"' % target))
+        print((red('WARNING: Could not restart service "%s"' % target)))
 
 @task
 @hosts(INSTALLATION_HOST)
diff --git a/patzilla/access/cipo/drawing.py b/patzilla/access/cipo/drawing.py
index f15d59c4..3eb22f75 100644
--- a/patzilla/access/cipo/drawing.py
+++ b/patzilla/access/cipo/drawing.py
@@ -3,7 +3,7 @@
 import re
 import logging
 import requests
-from BeautifulSoup import BeautifulSoup
+from bs4 import BeautifulSoup
 from patzilla.util.numbers.common import split_patent_number
 
 log = logging.getLogger(__name__)
@@ -70,7 +70,7 @@ def get_first_drawing_url(patent):
     images_index_html = fetch_images_index(images_index_url)
     soup = BeautifulSoup(images_index_html)
     # <img src="/opic-cipo/cpd/page/141597_20130713_drawings_page1_scale25_rotate0.gif?page=3&amp;section=drawings&amp;scale=25&amp;rotation=0&amp;type=" alt="Canadian Patent Document 141597. Drawings page. Image 1 of 3" />
-    first_drawing_url = cipo_baseurl + soup.find('img', src=re.compile(ur'/opic-cipo/cpd/page'))['src']
+    first_drawing_url = cipo_baseurl + soup.find('img', src=re.compile(r'/opic-cipo/cpd/page'))['src']
 
     return first_drawing_url
 
@@ -83,6 +83,6 @@ def get_first_drawing_url(patent):
         payload = fetch_first_drawing(split_patent_number(number))
         if payload:
             #print "payload length:", len(payload)
-            print payload
+            print(payload)
         else:
-            print "not found"
+            print("not found")
diff --git a/patzilla/access/depatech/client.py b/patzilla/access/depatech/client.py
index 652bd6e1..011edff6 100644
--- a/patzilla/access/depatech/client.py
+++ b/patzilla/access/depatech/client.py
@@ -13,7 +13,7 @@
 from patzilla.access.depatech import get_depatech_client
 from patzilla.access.generic.exceptions import NoResultsException, GenericAdapterException, SearchException
 from patzilla.access.generic.search import GenericSearchResponse, GenericSearchClient
-from patzilla.util.data.container import SmartBunch
+from patzilla.util.data.container import SmartMunch
 from patzilla.util.numbers.normalize import normalize_patent
 
 log = logging.getLogger(__name__)
@@ -55,7 +55,7 @@ def search(self, query, options=None):
         return self.search_real(query, options=options)
 
     def search_real(self, query, options=None):
-        options = options or SmartBunch()
+        options = options or SmartMunch()
 
         options.setdefault('offset', 0)
         options.setdefault('limit', self.pagesize)
@@ -73,7 +73,7 @@ def search_real(self, query, options=None):
             transport = 'json'
             query.expression = self.translate_deparom_query(query.expression)
 
-        log.info(u"{backend_name}: searching documents, expression='{0}', offset={1}, limit={2}; user={username}".format(
+        log.info("{backend_name}: searching documents, expression='{0}', offset={1}, limit={2}; user={username}".format(
             query.expression, offset, limit, **self.__dict__))
 
         starttime = timeit.default_timer()
@@ -92,7 +92,7 @@ def search_real(self, query, options=None):
             'from': offset, 'size': limit,
         }
 
-        log.info(u'{backend_name}: query={query}, uri={uri}, params={params}, options={options}'.format(
+        log.info('{backend_name}: query={query}, uri={uri}, params={params}, options={options}'.format(
             query=query, uri=uri, params=params, options=options.dump(), backend_name=self.backend_name))
 
         # Perform search request
@@ -164,10 +164,10 @@ def search_real(self, query, options=None):
                 if 'reason' not in upstream_error:
                     upstream_error['reason'] = 'Reason unknown'
 
-                message = u'Response status code: {code}\n\n{reason}'.format(**upstream_error)
+                message = 'Response status code: {code}\n\n{reason}'.format(**upstream_error)
 
                 raise self.search_failed(
-                    user_info=u'Error searching depa.tech.',
+                    user_info='Error searching depa.tech.',
                     message=message,
                     response=response)
 
@@ -180,7 +180,7 @@ def translate_deparom_query(self, expression):
 
         expression = expression.replace(upstream_prefix, '').replace('deparom:', '')
 
-        log.info(u'{backend_name}: Translate DEPAROM query expression={expression}, uri={uri}'.format(
+        log.info('{backend_name}: Translate DEPAROM query expression={expression}, uri={uri}'.format(
             expression=expression, uri=uri, backend_name=self.backend_name))
 
         expression = upstream_prefix + expression
@@ -212,7 +212,7 @@ def translate_deparom_query(self, expression):
 
         elif response.status_code >= 400:
 
-            message = u'Reason unknown'
+            message = 'Reason unknown'
 
             if response.headers.get('Content-Type', '').startswith('application/json'):
 
@@ -224,15 +224,15 @@ def translate_deparom_query(self, expression):
                     upstream_error['code'] = response_data['status']
 
                     if 'reason' not in upstream_error:
-                        upstream_error['reason'] = u'Reason unknown'
+                        upstream_error['reason'] = 'Reason unknown'
 
-                    message = u'Response status code: {code}\n\n{reason}'.format(**upstream_error)
+                    message = 'Response status code: {code}\n\n{reason}'.format(**upstream_error)
 
             else:
                 message = response.content
 
             raise self.search_failed(
-                user_info=u'Translating DEPAROM query expression failed',
+                user_info='Translating DEPAROM query expression failed',
                 message=message,
                 response=response)
 
@@ -298,8 +298,8 @@ def read(self):
             'name': 'depatech',
             'time': self.input['took'],
             'status': 'success',
-            #'params': SmartBunch.bunchify(self.input['content']['responseHeader']['params']),
-            #'pager': SmartBunch.bunchify(self.input['content']['responseHeader'].get('pager', {})),
+            #'params': SmartMunch.munchify(self.input['content']['responseHeader']['params']),
+            #'pager': SmartMunch.munchify(self.input['content']['responseHeader'].get('pager', {})),
         })
 
         self.meta.navigator.count_total = int(self.input['hits']['total'])
@@ -307,14 +307,14 @@ def read(self):
         self.meta.navigator.offset      = int(self.options.offset)
         self.meta.navigator.limit       = int(self.options.limit)
         self.meta.navigator.max_hits   = int(self.options.max_hits)
-        self.meta.navigator.postprocess = SmartBunch()
+        self.meta.navigator.postprocess = SmartMunch()
 
         # Read content
         self.documents = self.input['hits']['hits']
         self.read_documents()
 
     def document_to_number(self, document):
-        _id = document[u'_id']
+        _id = document['_id']
         cc, docno, kindcode = _id.split('.')
         publication_number = cc + docno + kindcode
         number = normalize_patent(publication_number)
@@ -326,7 +326,7 @@ def document_to_family_id(self, document):
 
 def depatech_search(query, options=None):
 
-    options = options or SmartBunch()
+    options = options or SmartMunch()
 
     client = get_depatech_client()
     try:
diff --git a/patzilla/access/depatech/clientpool.py b/patzilla/access/depatech/clientpool.py
index 223d094d..62599608 100644
--- a/patzilla/access/depatech/clientpool.py
+++ b/patzilla/access/depatech/clientpool.py
@@ -3,8 +3,8 @@
 import logging
 import os
 from pyramid.httpexceptions import HTTPUnauthorized
-from zope.interface.declarations import implements
 from zope.interface.interface import Interface
+from zope.interface import implementer
 from patzilla.access.depatech.client import DepaTechClient
 from patzilla.access.generic.credentials import AbstractCredentialsGetter, DatasourceCredentialsManager
 
@@ -43,6 +43,8 @@ def from_settings(datasource_settings):
 
     @staticmethod
     def from_environment():
+        if not os.environ["DEPATECH_API_USERNAME"] or not os.environ["DEPATECH_API_PASSWORD"]:
+            raise KeyError("DEPATECH_API_USERNAME or DEPATECH_API_PASSWORD is empty")
         return {
             "api_username": os.environ["DEPATECH_API_USERNAME"],
             "api_password": os.environ["DEPATECH_API_PASSWORD"],
@@ -78,13 +80,12 @@ class IDepaTechClientPool(Interface):
     pass
 
 
+@implementer(IDepaTechClientPool)
 class DepaTechClientPool(object):
     """
     depa.tech client pool as Pyramid utility implementation.
     """
 
-    implements(IDepaTechClientPool)
-
     def __init__(self, api_uri):
         logger.info("Creating upstream client pool for depa.tech")
         self.api_uri = api_uri
diff --git a/patzilla/access/depatech/expression.py b/patzilla/access/depatech/expression.py
index ef6cebde..c6cd8491 100644
--- a/patzilla/access/depatech/expression.py
+++ b/patzilla/access/depatech/expression.py
@@ -21,7 +21,7 @@
 class DepaTechGrammar(CQLGrammar):
     def preconfigure(self):
         CQLGrammar.preconfigure(self)
-        self.cmp_single = u':'.split()
+        self.cmp_single = ':'.split()
 
 
 class DepaTechParser(object):
@@ -161,7 +161,7 @@ def pair_to_elasticsearch(cls, key, value, modifiers=None):
             return
 
         expression = None
-        format = u'{0}:{1}'
+        format = '{0}:{1}'
 
 
         # ------------------------------------------
@@ -184,20 +184,20 @@ def pair_to_elasticsearch(cls, key, value, modifiers=None):
                 patent = patent_normalized
 
             if patent:
-                subexpression = u'PC:{country} AND DE:{number}'.format(**patent)
+                subexpression = 'PC:{country} AND DE:{number}'.format(**patent)
                 if patent['kind']:
-                    subexpression += u' AND KI:{kind}'.format(**patent)
-                expression_parts.append(u'({})'.format(subexpression))
+                    subexpression += ' AND KI:{kind}'.format(**patent)
+                expression_parts.append('({})'.format(subexpression))
 
             # Application number
-            subexpression = u'AN:{}'.format(value)
+            subexpression = 'AN:{}'.format(value)
             expression_parts.append(subexpression)
-            expression = u' OR '.join(expression_parts)
+            expression = ' OR '.join(expression_parts)
 
             # Priority number
-            subexpression = u'NP:{}'.format(value)
+            subexpression = 'NP:{}'.format(value)
             expression_parts.append(subexpression)
-            expression = u' OR '.join(expression_parts)
+            expression = ' OR '.join(expression_parts)
 
         elif key == 'pubdate':
 
@@ -212,7 +212,7 @@ def pair_to_elasticsearch(cls, key, value, modifiers=None):
 
                 # e.g. 1991
                 if len(value) == 4 and value.isdigit():
-                    value = u'within {}0101,{}1231'.format(value, value)
+                    value = 'within {}0101,{}1231'.format(value, value)
 
                 # e.g. 1990-2014, 1990 - 2014
                 value = year_range_to_within(value)
@@ -249,12 +249,12 @@ def pair_to_elasticsearch(cls, key, value, modifiers=None):
 
             except Exception as ex:
                 message = 'depatech query: Invalid date or range expression "{0}". Reason: {1}.'.format(value, ex)
-                logger.warn(message + ' Exception was: {0}'.format(_exception_traceback()))
+                logger.warning(message + ' Exception was: {0}'.format(_exception_traceback()))
                 return {'error': True, 'message': message}
 
         elif key == 'inventor' or key == 'applicant':
             if not has_booleans(value) and should_be_quoted(value):
-                value = u'"{0}"'.format(value)
+                value = '"{0}"'.format(value)
 
         elif key == 'class':
 
@@ -268,7 +268,7 @@ def pair_to_elasticsearch(cls, key, value, modifiers=None):
 
                 # Put value into parenthesis, to properly capture expressions
                 if value:
-                    value = u'({value})'.format(value=value)
+                    value = '({value})'.format(value=value)
 
                 # Parse value as simple query expression
                 query_object = CQL(cql=value)
@@ -290,7 +290,7 @@ def pair_to_elasticsearch(cls, key, value, modifiers=None):
         # ------------------------------------------
         if key in ['fulltext', 'inventor', 'applicant', 'country', 'citation']:
             if has_booleans(value) and not should_be_quoted(value):
-                value = u'({0})'.format(value)
+                value = '({0})'.format(value)
 
         # ------------------------------------------
         #   expression formatter
@@ -358,15 +358,15 @@ def triple_callback(token, index, binop, term):
 
 def format_expression(format, fieldname, value):
     expression = None
-    if type(fieldname) in types.StringTypes:
+    if type(fieldname) in (str,):
         expression = format.format(fieldname, value)
-    elif type(fieldname) is types.ListType:
+    elif type(fieldname) is list:
         subexpressions = []
         for fieldname in fieldname:
             subexpressions.append(format.format(fieldname, value))
         expression = ' or '.join(subexpressions)
         # surround with parentheses
-        expression = u'({0})'.format(expression)
+        expression = '({0})'.format(expression)
     return expression
 
 def lucene_convert_class(value):
@@ -395,4 +395,4 @@ def should_be_quoted(value):
 
 
 if __name__ == '__main__':
-    print DepaTechParser('IC:G01F000184').keywords
+    print(DepaTechParser('IC:G01F000184').keywords)
diff --git a/patzilla/access/depatech/expression.rst b/patzilla/access/depatech/expression.rst
index eed14b55..78adcac3 100644
--- a/patzilla/access/depatech/expression.rst
+++ b/patzilla/access/depatech/expression.rst
@@ -20,30 +20,30 @@ Empty query
 IPC/CPC
 =======
 >>> DepaTechParser('H01F7/00').dumps()
-u'H01F7/00'
+'H01F7/00'
 
 # Rewrite all patent classifications from depa.tech format to OPS format
 >>> DepaTechParser('IC:G01F000184').parse().rewrite_classes_ops().dumps()
-u'IC : G01F1/84'
+'IC : G01F1/84'
 
 >>> DepaTechParser('IC:G01F000184').keywords
-[u'G01F1/84']
+['G01F1/84']
 
 >>> DepaTechExpression.pair_to_elasticsearch('class', 'H04L12/433 or H04L12/24')
-{'query': u'((IC:H04L0012433 OR NC:H04L0012433) OR (IC:H04L001224 OR NC:H04L001224))'}
+{'query': '((IC:H04L0012433 OR NC:H04L0012433) OR (IC:H04L001224 OR NC:H04L001224))'}
 
 >>> DepaTechExpression.pair_to_elasticsearch('class', 'H01F7/00 or (H01F7/02 and H02K7/1876)')
-{'query': u'((IC:H01F000700 OR NC:H01F000700) OR ((IC:H01F000702 OR NC:H01F000702) AND (IC:H02K00071876 OR NC:H02K00071876)))'}
+{'query': '((IC:H01F000700 OR NC:H01F000700) OR ((IC:H01F000702 OR NC:H01F000702) AND (IC:H02K00071876 OR NC:H02K00071876)))'}
 
 >>> DepaTechExpression.pair_to_elasticsearch('class', 'H01F7/00 not (H01F7/02 or H02K7/1876)')
-{'query': u'((IC:H01F000700 OR NC:H01F000700) NOT ((IC:H01F000702 OR NC:H01F000702) OR (IC:H02K00071876 OR NC:H02K00071876)))'}
+{'query': '((IC:H01F000700 OR NC:H01F000700) NOT ((IC:H01F000702 OR NC:H01F000702) OR (IC:H02K00071876 OR NC:H02K00071876)))'}
 
 
 Publication date
 ================
 
 >>> DepaTechExpression.pair_to_elasticsearch('pubdate', 'foobar')
-{'message': 'depatech query: Invalid date or range expression "foobar". Reason: foobar.', 'error': True}
+{'error': True, 'message': 'depatech query: Invalid date or range expression "foobar". Reason: foobar.'}
 
 
 *********
@@ -54,39 +54,39 @@ Simple expressions
 ==================
 
 >>> DepaTechParser('GT:bildschirm').keywords
-[u'bildschirm']
+['bildschirm']
 
 >>> DepaTechExpression.pair_to_elasticsearch('fulltext', 'bildschirm')
-{'query': u'(AB:bildschirm OR GT:bildschirm OR ET:bildschirm OR FT:bildschirm)'}
+{'query': '(AB:bildschirm OR GT:bildschirm OR ET:bildschirm OR FT:bildschirm)'}
 
 
 >>> DepaTechParser('GT:bildschirm or AB:fahrzeug').keywords
-[u'bildschirm', u'fahrzeug']
+['bildschirm', 'fahrzeug']
 
 >>> DepaTechExpression.pair_to_elasticsearch('fulltext', 'bildschirm or fahrzeug')
-{'query': u'(AB:(bildschirm OR fahrzeug) OR GT:(bildschirm OR fahrzeug) OR ET:(bildschirm OR fahrzeug) OR FT:(bildschirm OR fahrzeug))'}
+{'query': '(AB:(bildschirm OR fahrzeug) OR GT:(bildschirm OR fahrzeug) OR ET:(bildschirm OR fahrzeug) OR FT:(bildschirm OR fahrzeug))'}
 
 
 >>> DepaTechParser('GT:bildschirm and AB:(fahrzeug or pkw)').keywords
-[u'bildschirm', u'fahrzeug', u'pkw']
+['bildschirm', 'fahrzeug', 'pkw']
 
 >>> DepaTechExpression.pair_to_elasticsearch('fulltext', 'bildschirm and (fahrzeug or pkw)')
-{'query': u'(AB:(bildschirm AND (fahrzeug OR pkw)) OR GT:(bildschirm AND (fahrzeug OR pkw)) OR ET:(bildschirm AND (fahrzeug OR pkw)) OR FT:(bildschirm AND (fahrzeug OR pkw)))'}
+{'query': '(AB:(bildschirm AND (fahrzeug OR pkw)) OR GT:(bildschirm AND (fahrzeug OR pkw)) OR ET:(bildschirm AND (fahrzeug OR pkw)) OR FT:(bildschirm AND (fahrzeug OR pkw)))'}
 
 
 >>> DepaTechParser('GT:bildschirm and AB:(fahrzeug or pkw not lkw)').keywords
-[u'bildschirm', u'fahrzeug', u'pkw', u'lkw']
+['bildschirm', 'fahrzeug', 'pkw', 'lkw']
 
 >>> DepaTechExpression.pair_to_elasticsearch('fulltext', 'bildschirm and (fahrzeug or pkw not lkw)')
-{'query': u'(AB:(bildschirm AND (fahrzeug OR pkw NOT lkw)) OR GT:(bildschirm AND (fahrzeug OR pkw NOT lkw)) OR ET:(bildschirm AND (fahrzeug OR pkw NOT lkw)) OR FT:(bildschirm AND (fahrzeug OR pkw NOT lkw)))'}
+{'query': '(AB:(bildschirm AND (fahrzeug OR pkw NOT lkw)) OR GT:(bildschirm AND (fahrzeug OR pkw NOT lkw)) OR ET:(bildschirm AND (fahrzeug OR pkw NOT lkw)) OR FT:(bildschirm AND (fahrzeug OR pkw NOT lkw)))'}
 
 
 >>> DepaTechParser('AB:fahrzeug or AB:pkw').keywords
-[u'fahrzeug', u'pkw']
+['fahrzeug', 'pkw']
 
 
 >>> DepaTechParser('AB:fahrzeug not GT:pkw').keywords
-[u'fahrzeug', u'pkw']
+['fahrzeug', 'pkw']
 
 
 
@@ -97,17 +97,17 @@ Queries without proper fieldnames like AB:, GT:, AB:, etc. on the left side of t
 
 
 >>> DepaTechParser('bildschirm').dumps()
-u'bildschirm'
+'bildschirm'
 
 >>> DepaTechExpression.pair_to_elasticsearch('fulltext', 'bildschirm')
-{'query': u'(AB:bildschirm OR GT:bildschirm OR ET:bildschirm OR FT:bildschirm)'}
+{'query': '(AB:bildschirm OR GT:bildschirm OR ET:bildschirm OR FT:bildschirm)'}
 
 
 >>> DepaTechParser('bildschirm and fahrzeug').dumps()
-u'bildschirm and fahrzeug'
+'bildschirm and fahrzeug'
 
 >>> DepaTechExpression.pair_to_elasticsearch('fulltext', 'bildschirm and fahrzeug')
-{'query': u'(AB:(bildschirm AND fahrzeug) OR GT:(bildschirm AND fahrzeug) OR ET:(bildschirm AND fahrzeug) OR FT:(bildschirm AND fahrzeug))'}
+{'query': '(AB:(bildschirm AND fahrzeug) OR GT:(bildschirm AND fahrzeug) OR ET:(bildschirm AND fahrzeug) OR FT:(bildschirm AND fahrzeug))'}
 
 
 
@@ -115,22 +115,22 @@ Expressions containing quoted words
 ===================================
 
 >>> DepaTechParser('"bildschirm"').dumps()
-u'"bildschirm"'
+'"bildschirm"'
 
 >>> DepaTechParser('"bildschirm"').keywords
 []
 
 >>> DepaTechExpression.pair_to_elasticsearch('fulltext', '"bildschirm"')
-{'query': u'(AB:"bildschirm" OR GT:"bildschirm" OR ET:"bildschirm" OR FT:"bildschirm")'}
+{'query': '(AB:"bildschirm" OR GT:"bildschirm" OR ET:"bildschirm" OR FT:"bildschirm")'}
 
 >>> DepaTechParser('AB:"bildschirm"').dumps()
-u'AB : "bildschirm"'
+'AB : "bildschirm"'
 
 >>> DepaTechParser('AB:"bildschirm"').keywords
-[u'bildschirm']
+['bildschirm']
 
 >>> DepaTechParser('AB:(("aussto*" OR "eject*" OR pusher*) AND (verriegel* OR lock* OR sperr*))').keywords
-[u'aussto', u'eject', u'pusher', u'verriegel', u'lock', u'sperr']
+['aussto', 'eject', 'pusher', 'verriegel', 'lock', 'sperr']
 
 
 
@@ -138,19 +138,19 @@ Keyword extraction
 ==================
 
 >>> DepaTechParser(DepaTechExpression.pair_to_elasticsearch('class', 'H01F7/00')['query']).keywords
-[u'H01F7/00']
+['H01F7/00']
 
 >>> DepaTechParser(DepaTechExpression.pair_to_elasticsearch('class', 'H01F7/00 not (H01F7/02 or H02K7/1876)')['query']).keywords
-[u'H01F7/00', u'H01F7/02', u'H02K7/1876']
+['H01F7/00', 'H01F7/02', 'H02K7/1876']
 
 >>> DepaTechParser(DepaTechExpression.pair_to_elasticsearch('fulltext', 'bildschirm')['query']).keywords
-[u'bildschirm']
+['bildschirm']
 
 >>> DepaTechParser(DepaTechExpression.pair_to_elasticsearch('fulltext', '"bildschirm"')['query']).keywords
-[u'bildschirm']
+['bildschirm']
 
 >>> DepaTechParser(DepaTechExpression.pair_to_elasticsearch('fulltext', 'GT:bildschirm OR AB:(fahrzeug OR pkw)')['query']).keywords
-[u'bildschirm', u'fahrzeug', u'pkw']
+['bildschirm', 'fahrzeug', 'pkw']
 
 
 
@@ -160,18 +160,18 @@ From the wild
 Umlauts
 -------
 
->>> DepaTechParser(u'AB:((*messschieber* OR *meßschieber*) AND *digital* )').dumps()
-u'((AB : *messschieber* or AB : *me\xdfschieber*) and AB : *digital*)'
+>>> DepaTechParser('AB:((*messschieber* OR *meßschieber*) AND *digital* )').dumps()
+'((AB : *messschieber* or AB : *me\xdfschieber*) and AB : *digital*)'
 
->>> DepaTechParser(u'AB:((*messschieber* OR *meßschieber*) AND *digital* )').keywords
-[u'messschieber', u'me\xdfschieber', u'digital']
+>>> DepaTechParser('AB:((*messschieber* OR *meßschieber*) AND *digital* )').keywords
+['messschieber', 'me\xdfschieber', 'digital']
 
 
 More
 ----
 
->>> DepaTechParser(u'ET:(energy and water) or AB:(waves or Tide) and AB:"90°"').keywords
-[u'energy', u'water', u'waves', u'Tide', u'90\xb0']
+>>> DepaTechParser('ET:(energy and water) or AB:(waves or Tide) and AB:"90°"').keywords
+['energy', 'water', 'waves', 'Tide', '90\xb0']
 
->>> DepaTechParser(u'AB:(((bremsgefühl* or pedalgefühl) and (*simulator or simul*)) and (separ* or getrennt* or entkoppel* or entkoppl* or decoupl*) and (eigenständig* or independent* or autonom*))').keywords
-[u'bremsgef\xfchl', u'pedalgef\xfchl', u'simulator', u'simul', u'separ', u'getrennt', u'entkoppel', u'entkoppl', u'decoupl', u'eigenst\xe4ndig', u'independent', u'autonom']
+>>> DepaTechParser('AB:(((bremsgefühl* or pedalgefühl) and (*simulator or simul*)) and (separ* or getrennt* or entkoppel* or entkoppl* or decoupl*) and (eigenständig* or independent* or autonom*))').keywords
+['bremsgef\xfchl', 'pedalgef\xfchl', 'simulator', 'simul', 'separ', 'getrennt', 'entkoppel', 'entkoppl', 'decoupl', 'eigenst\xe4ndig', 'independent', 'autonom']
diff --git a/patzilla/access/dpma/depatisconnect.py b/patzilla/access/dpma/depatisconnect.py
index 0065bb25..0d42d769 100644
--- a/patzilla/access/dpma/depatisconnect.py
+++ b/patzilla/access/dpma/depatisconnect.py
@@ -4,9 +4,9 @@
 import json
 import logging
 import requests
-import xmlrpclib
-from StringIO import StringIO
-from ConfigParser import NoOptionError
+import xmlrpc.client
+from io import StringIO
+from configparser import NoOptionError
 from lxml import etree as ET
 from lxml.builder import E
 from cornice.util import to_list
@@ -72,7 +72,7 @@ def run_acquisition(document_number, doctypes=None):
     url = archive_service_baseurl + '/RPC2'
     transport = RequestsTransport(session=get_client(), timeout=(2, 17))
     transport.use_https = use_https
-    server = xmlrpclib.ServerProxy(url, transport=transport)
+    server = xmlrpc.client.ServerProxy(url, transport=transport)
     return server.runAcquisition(numbers, doctypes)
 
 def fetch_xml(number):
@@ -313,4 +313,4 @@ def depatisconnect_abstracts(document_number, language=None, invalidate=False):
     # Failed on 2018-04-23
     #response = depatisconnect_claims('USD813591S')
 
-    print json.dumps(response)
+    print(json.dumps(response))
diff --git a/patzilla/access/dpma/depatisnet.py b/patzilla/access/dpma/depatisnet.py
index 1b000fa3..4b0f42cc 100644
--- a/patzilla/access/dpma/depatisnet.py
+++ b/patzilla/access/dpma/depatisnet.py
@@ -1,15 +1,15 @@
 # -*- coding: utf-8 -*-
 # (c) 2014-2015 Andreas Motl, Elmyra UG <andreas.motl@elmyra.de>
-import re
 import sys
 import json
 import types
 import logging
-import urllib2
+import urllib.request, urllib.error, urllib.parse
 import mechanize
-import cookielib
-from BeautifulSoup import BeautifulSoup
-from xlrd import open_workbook
+import re
+import http.cookiejar
+from bs4 import BeautifulSoup
+from xlrd3 import open_workbook
 from patzilla.access.generic.search import GenericSearchResponse
 from patzilla.util.date import from_german, date_iso
 from patzilla.util.network.browser import regular_user_agent
@@ -44,7 +44,7 @@ class DpmaDepatisnetAccess:
     ]
 
     def __init__(self):
-        print 'DpmaDepatisnetAccess.__init__'
+        print('DpmaDepatisnetAccess.__init__')
         self.baseurl = 'https://depatisnet.dpma.de/DepatisNet'
         self.searchurl_cql    = self.baseurl + '/depatisnet?action=experte&switchToLang=en'
         self.searchurl_ikofax = self.baseurl + '/depatisnet?action=ikofax&switchToLang=en'
@@ -65,7 +65,7 @@ def setup_browser(self):
         # http://wwwsearch.sourceforge.net/mechanize/
         # https://github.com/python-mechanize/mechanize
         self.browser = mechanize.Browser()
-        self.browser.set_cookiejar(cookielib.LWPCookieJar())
+        self.browser.set_cookiejar(http.cookiejar.LWPCookieJar())
         self.browser.addheaders = [('User-Agent', regular_user_agent)]
         # ignore robots.txt
         self.browser.set_handle_robots(False)
@@ -85,7 +85,7 @@ def search_patents(self, query, options=None):
         limit = options.get('limit')
         max_hits = options.get('max_hits')
 
-        logger.info(u'Searching documents. query="%s", options=%s' % (query, options))
+        logger.info('Searching documents. query="%s", options=%s' % (query, options))
 
         # 0. create browser instance
         if not self.browser:
@@ -97,7 +97,7 @@ def search_patents(self, query, options=None):
             search_url = self.searchurl_ikofax
         try:
             self.browser.open(search_url)
-        except urllib2.HTTPError as ex:
+        except urllib.error.HTTPError as ex:
             logger.critical('Hard error with DEPATISnet: {}'.format(ex))
             self.logout()
             raise
@@ -107,7 +107,7 @@ def search_patents(self, query, options=None):
         self.browser.select_form(nr=0)
         #self.browser.select_form(name='form')
 
-        self.browser['query'] = query.encode('iso-8859-1')
+        self.browser['query'] = query
         self.browser['hitsPerPage'] = [str(limit)]
         self.browser['maxHitsUser'] = [str(max_hits)]
 
@@ -127,7 +127,7 @@ def search_patents(self, query, options=None):
         #self.browser['so'] = ['desc']
 
         # sort by user selection
-        if 'sorting' in options and type(options['sorting']) is types.DictionaryType:
+        if 'sorting' in options and type(options['sorting']) is dict:
             self.browser['sf'] = [options['sorting']['field']]
             self.browser['so'] = [options['sorting']['order']]
 
@@ -197,7 +197,7 @@ def search_patents(self, query, options=None):
                 results = self.read_xls_response(xls_response)
             except Exception as ex:
                 logger.error('Problem downloading results in XLS format: {}'.format(ex))
-                ex.http_response = ex.read()
+                #ex.http_response = ex.read()
                 raise
 
             # debugging
@@ -225,22 +225,24 @@ def find_errors(self, body):
                               'otherwise don\'t hesitate to report this problem to us.')
 
         # Check for error messages
-        soup = BeautifulSoup(body)
+        soup = BeautifulSoup(body, 'lxml')
         error_message = soup.find('div', {'id': 'errormsg'})
         if error_message:
             parts = []
             [s.extract() for s in error_message('a')]
             [parts.append(s.extract()) for s in error_message('p', {'class': 'headline'})]
             reason = ', '.join([part.getText() for part in parts])
-            error_message = u'{}\n{}'.format(reason, str(error_message))
+            error_message = '{}\n{}'.format(reason, str(error_message))
         else:
             error_message = ''
 
-        if u'An error has occurred' in body:
-            error_message = error_message.replace('\t', '').replace('\r\n', '\n').strip()
+        # Compute error message.
+        prefix = 'Upstream service: '
+        if 'An error has occurred' in body:
+            error_message = prefix + error_message.replace('\t', '').replace('\r\n', '\n').strip()
             raise SyntaxError(error_message)
 
-        return error_message
+        return prefix + error_message
 
     def read_xls_response(self, xls_response):
         data = excel_to_dict(xls_response.read())
@@ -307,8 +309,8 @@ def read(self):
             # TODO: Reference from IFI CLAIMS, fill up/unify.
             #'time': self.input['time'],
             #'status': self.input['status'],
-            #'params': SmartBunch.bunchify(self.input['content']['responseHeader']['params']),
-            #'pager': SmartBunch.bunchify(self.input['content']['responseHeader'].get('pager', {})),
+            #'params': SmartMunch.munchify(self.input['content']['responseHeader']['params']),
+            #'pager': SmartMunch.munchify(self.input['content']['responseHeader'].get('pager', {})),
         })
 
         self.meta.navigator.count_total = int(self.input['hits'])
@@ -317,7 +319,7 @@ def read(self):
         # TODO: Fill up?
         #self.meta.navigator.offset      = int(self.meta.upstream.Offset)
         #self.meta.navigator.limit       = int(self.meta.upstream.Limit)
-        #self.meta.navigator.postprocess = SmartBunch()
+        #self.meta.navigator.postprocess = SmartMunch()
 
 
         # Propagate user message
@@ -355,17 +357,17 @@ def excel_to_dict(payload):
     start_row = 0
 
     # upstream added new status line to first row, e.g. "Search query: pn=(EP666666) Status: 25.09.2015"
-    if u'Search query' in sheet.cell(0, 0).value:
+    if 'Search query' in sheet.cell(0, 0).value:
         start_row = 1
 
     # read header values
-    keys = [sheet.cell(start_row, col_index).value for col_index in xrange(sheet.ncols)]
+    keys = [sheet.cell(start_row, col_index).value for col_index in range(sheet.ncols)]
 
     # read sheet content
     dict_list = []
-    for row_index in xrange(start_row + 1, sheet.nrows):
+    for row_index in range(start_row + 1, sheet.nrows):
         d = {keys[col_index]: sheet.cell(row_index, col_index).value
-             for col_index in xrange(sheet.ncols)}
+             for col_index in range(sheet.ncols)}
         dict_list.append(d)
 
     return dict_list
@@ -390,4 +392,4 @@ def excel_to_dict(payload):
     else:
         data = depatisnet.search_patents('BI=bagger and PC=DE')
 
-    print json.dumps(data)
+    print(json.dumps(data))
diff --git a/patzilla/access/dpma/dpmaregister.py b/patzilla/access/dpma/dpmaregister.py
index a662ef49..cd12451f 100644
--- a/patzilla/access/dpma/dpmaregister.py
+++ b/patzilla/access/dpma/dpmaregister.py
@@ -11,12 +11,12 @@
 import operator
 import mechanicalsoup
 from beaker.cache import cache_region
-from bunch import bunchify
+from munch import munchify
 from docopt import docopt
 from pprint import pformat
 from jsonpointer import JsonPointer, JsonPointerException
 from xml.etree.ElementTree import fromstring
-from BeautifulSoup import BeautifulSoup
+from bs4 import BeautifulSoup
 from collections import namedtuple, OrderedDict
 from patzilla.access.dpma.util import dpma_file_number
 from patzilla.boot.cache import configure_cache_backend
@@ -247,7 +247,7 @@ def search_patent(self, patent):
         # has to be adjusted.
         time.sleep(1.0)
 
-        if "/TSPD" in self.response.content:
+        if b"/TSPD" in self.response.content:
             raise ValueError("Site is protected by F5 Advanced WAF")
 
         # Debugging
@@ -283,7 +283,7 @@ def search_patent(self, patent):
             return [entry]
 
         # Sanity checks
-        if "<span>0 result/s</span>" in response.content:
+        if b"<span>0 result/s</span>" in response.content:
             msg = 'No search results for "{}"'.format(patent)
             logger.warning(msg)
             raise NoResults(msg)
@@ -311,7 +311,7 @@ def parse_reference_link(self, link, patent):
             msg = "Could not parse document reference from link '%s' (patent='%s')" % (link, patent)
             logger.error(msg)
             raise Exception(msg)
-        label = link.find(text=True)
+        label = link.find(string=True)
         return reference, label
 
     def fetch_reference(self, result, language):
@@ -369,7 +369,7 @@ def html_compact(self):
         <a shape="rect" class="button" target="_blank" href="register?AKZ=100068189&amp;VIEW=pdf">PDF-Download</a>
         """
 
-        soup = BeautifulSoup(self.html)
+        soup = BeautifulSoup(self.html, "lxml")
 
         soup_content = soup.find('table', {'id': 'verfahrensdaten_tabelle'})
 
@@ -528,13 +528,13 @@ def decode(self):
         self.decode_badgerfish()
 
         # Document numbers
-        self.application_reference = map(
+        self.application_reference = list(map(
             operator.itemgetter('document_id'),
-            self.convert_list(self.query_data(self.pointer_application_reference)))
+            self.convert_list(self.query_data(self.pointer_application_reference))))
 
-        self.publication_reference = map(
+        self.publication_reference = list(map(
             operator.itemgetter('document_id'),
-            self.convert_list(self.query_data(self.pointer_publication_reference)))
+            self.convert_list(self.query_data(self.pointer_publication_reference))))
 
         # Classifications
         self.classifications['ipcr'] = self.convert_list(self.query_data(self.pointer_classifications_ipcr))
@@ -565,9 +565,9 @@ def decode(self):
         self.designated_states = self.convert_list(self.query_data(self.pointer_designated_states))
 
         # Citations
-        self.references_cited = map(
+        self.references_cited = list(map(
             operator.attrgetter('document_id.doc_number'),
-            bunchify(self.convert_list(self.query_data(self.pointer_references_cited))))
+            munchify(self.convert_list(self.query_data(self.pointer_references_cited)))))
 
         # office-specific-bib-data
         self.office_specific_bibdata = self.convert_dict(self.query_data(self.pointer_office_specific_bibdata))
@@ -590,7 +590,7 @@ def convert_list(cls, things_raw, nested_element='$'):
         things = []
         for thing in to_list(things_raw):
             if not thing: continue
-            if nested_element in thing and len(thing.keys()) == 1:
+            if nested_element in thing and len(list(thing.keys())) == 1:
                 thing = thing[nested_element]
             if isinstance(thing, dict):
                 thing = cls.convert_dict(thing)
@@ -606,7 +606,7 @@ def convert_dict(cls, data):
             return {}
 
         newdata = OrderedDict()
-        for key, value in data.items():
+        for key, value in list(data.items()):
 
             # Decode nested text or recurse
             if '$' in value:
diff --git a/patzilla/access/epo/espacenet/client_html.py b/patzilla/access/epo/espacenet/client_html.py
index d5202db4..caa83a7f 100644
--- a/patzilla/access/epo/espacenet/client_html.py
+++ b/patzilla/access/epo/espacenet/client_html.py
@@ -97,7 +97,7 @@ def espacenet_fetch_html(document_number, section, element_id=None, element_clas
 
     else:
 
-        if 'Entity not found' in response.content:
+        if b'Entity not found' in response.content:
             raise KeyError(message_404)
         else:
             raise ValueError(message_fail)
diff --git a/patzilla/access/epo/espacenet/pyramid.py b/patzilla/access/epo/espacenet/pyramid.py
index db3038bb..b36da609 100644
--- a/patzilla/access/epo/espacenet/pyramid.py
+++ b/patzilla/access/epo/espacenet/pyramid.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # (c) 2015-2018 Andreas Motl, Elmyra UG
-from __future__ import absolute_import
+
 import logging
 from cornice.service import Service
 from pyramid.httpexceptions import HTTPBadRequest, HTTPNotFound
diff --git a/patzilla/access/epo/ops/api.py b/patzilla/access/epo/ops/api.py
index 5a11e3cf..e6da53c2 100644
--- a/patzilla/access/epo/ops/api.py
+++ b/patzilla/access/epo/ops/api.py
@@ -167,7 +167,7 @@ def match_filter(item, filter):
         original_publication_numbers += representation_pubrefs_docdb
 
         # Debugging
-        #print 'representation_pubref_epodoc:', representation_pubref_epodoc
+        #print( 'representation_pubref_epodoc:', representation_pubref_epodoc)
         #print 'representation_pubrefs_docdb:', representation_pubrefs_docdb
 
         # Fetch family members. When failing, use first cycle as representation.
@@ -310,7 +310,7 @@ def ops_published_data_search_real(constituents, query, range):
     ops = get_ops_client()
 
     # Send request to OPS.
-    range_begin, range_end = map(int, range.split('-'))
+    range_begin, range_end = list(map(int, range.split('-')))
     response = ops.published_data_search(
         query, range_begin=range_begin, range_end=range_end, constituents=to_list(constituents))
 
@@ -461,7 +461,7 @@ def image_representative_from_family(patent, countries, func_filter=None):
     # Compute alternative family members sorted by given countries
     alternatives = family.publications_by_country(exclude=[document], countries=countries)
     if func_filter:
-        alternatives = filter(func_filter, alternatives)
+        alternatives = list(filter(func_filter, alternatives))
 
     if alternatives:
         # TODO: Currently using first item as representative. This might change.
@@ -583,7 +583,7 @@ def inquire_images(document):
 
 
 def is_fulldocument(node):
-    return '@desc' in node and node['@desc'] == u'FullDocument'
+    return '@desc' in node and node['@desc'] == 'FullDocument'
 
 
 def is_amendment_only(node):
@@ -602,7 +602,7 @@ def is_amendment_only(node):
     """
     if is_fulldocument(node):
         sections = to_list(node.get('ops:document-section', []))
-        if len(sections) == 1 and sections[0]['@name'] == u'AMENDMENT':
+        if len(sections) == 1 and sections[0]['@name'] == 'AMENDMENT':
             return True
 
     return False
@@ -659,7 +659,7 @@ def get_ops_image(document, page, kind, format=None):
     # 1. Inquire images to compute url to image resource
     image_info = inquire_images(document)
     if image_info:
-        if image_info.has_key(kind):
+        if kind in image_info:
             drawing_node = image_info.get(kind)
             link = drawing_node['@link']
 
@@ -670,7 +670,7 @@ def get_ops_image(document, page, kind, format=None):
                     page = page + start_page - 1
 
         # fallback chain, if no drawings are available
-        elif image_info.has_key('JapaneseAbstract'):
+        elif 'JapaneseAbstract' in image_info:
             drawing_node = image_info.get('JapaneseAbstract')
             link = drawing_node['@link']
             page = 1
@@ -885,7 +885,7 @@ def handle_error(response, location):
 
     # Compute name
     name = 'http-response'
-    body = response_dict['content']
+    body = str(response_dict['content'],'UTF-8')
     if 'CLIENT.CQL' in body:
         name = 'expression'
 
@@ -901,44 +901,44 @@ def handle_error(response, location):
     response_json.status = response.status_code
 
     # countermeasure against "_JSONError: <unprintable _JSONError object>" or the like
-    response_json.detail = str(response.status_code) + ' ' + response.reason + ': ' + response.content
+    response_json.detail = str(response.status_code) + ' ' + str(response.reason) + ': ' + str(response.content)
 
     #print "response:", response
     if len(request.errors) == 1:
         error_info = request.errors[0].get('description')
         if error_info.get('status_code') == 404:
-            error_content = error_info.get('content', '')
+            error_content = error_info.get('content', b'')
             url = error_info.get('url')
             status = str(error_info.get('status_code', '')) + ' ' + error_info.get('reason', '')
 
-            if 'CLIENT.InvalidCountryCode' in error_content:
+            if b'CLIENT.InvalidCountryCode' in error_content:
                 ops_code = 'CLIENT.InvalidCountryCode'
-                message = u'OPS API response ({status}, {ops_code}). url={url}'.format(status=status, ops_code=ops_code, url=url)
+                message = 'OPS API response ({status}, {ops_code}). url={url}'.format(status=status, ops_code=ops_code, url=url)
                 log.error(message)
                 return response_json
 
-            if 'SERVER.EntityNotFound' in error_content:
+            if b'SERVER.EntityNotFound' in error_content:
                 ops_code = 'SERVER.EntityNotFound'
-                message = u'OPS API response ({status}, {ops_code}). url={url}'.format(status=status, ops_code=ops_code, url=url)
+                message = 'OPS API response ({status}, {ops_code}). url={url}'.format(status=status, ops_code=ops_code, url=url)
                 log.warning(message)
                 return response_json
 
-            if 'OPS - 404' in error_content or 'Page not found' in error_content:
+            if b'OPS - 404' in error_content or b'Page not found' in error_content:
                 ops_code = '404 OPS Page not found'
-                message = u'OPS API response ({status}, {ops_code}). url={url}'.format(status=status, ops_code=ops_code, url=url)
+                message = 'OPS API response ({status}, {ops_code}). url={url}'.format(status=status, ops_code=ops_code, url=url)
                 log.error(message)
-                log.error(u'OPS API errors:\n{}'.format(pformat(request.errors)))
+                log.error('OPS API errors:\n{}'.format(pformat(request.errors)))
                 response_json.status_code = 502
                 return response_json
 
-            if 'This API version is not supported' in error_content:
+            if b'This API version is not supported' in error_content:
                 ops_code = '404 API version not supported'
-                message = u'OPS API response ({status}, {ops_code}). url={url}'.format(status=status, ops_code=ops_code, url=url)
+                message = 'OPS API response ({status}, {ops_code}). url={url}'.format(status=status, ops_code=ops_code, url=url)
                 log.error(message)
                 response_json.status_code = 502
                 return response_json
 
-    log.error(u'OPS API errors:\n{}'.format(pformat(request.errors)))
+    log.error('OPS API errors:\n{}'.format(pformat(request.errors)))
 
     return response_json
 
@@ -972,7 +972,7 @@ def pdf_document_build(patent):
 
     # 3. add pdf metadata
     page_sections = None
-    if resource_info.has_key('ops:document-section'):
+    if 'ops:document-section' in resource_info:
         page_sections = resource_info['ops:document-section']
         #pprint(page_sections)
 
@@ -1028,7 +1028,7 @@ def ops_document_kindcodes(patent):
     for document in documents:
 
         # TODO: check whether a single occurrance of "not found" should really raise this exception
-        if document.has_key('@status') and document['@status'] == 'not found':
+        if '@status' in document and document['@status'] == 'not found':
             error = HTTPNotFound(error_msg_access)
             raise error
 
@@ -1080,7 +1080,7 @@ def analytics_family(query):
 
     # B. Enrich all family representatives
     # http://ops.epo.org/3.1/rest-services/family/application/docdb/US19288494.xml
-    for family_id, document_number in family_representatives.iteritems():
+    for family_id, document_number in family_representatives.items():
 
         payload.setdefault(family_id, {})
 
@@ -1246,7 +1246,7 @@ def __init__(self):
         self.items = []
 
     def __repr__(self):
-        return u'<{name} object at 0x{id}>\nitems:\n{items}'.format(name=self.__class__.__name__, id=id(self), items=pformat(self.items))
+        return '<{name} object at 0x{id}>\nitems:\n{items}'.format(name=self.__class__.__name__, id=id(self), items=pformat(self.items))
 
     def publications_by_country(self, exclude=None, countries=None):
         exclude = exclude or []
@@ -1290,13 +1290,13 @@ def _find_publication_number_by_prio_number():
 
 
 def _format_title(title):
-    return u'[{0}] {1}'.format(title.get(u'@lang', u'').upper() or u'', title[u'$'] or u'')
+    return '[{0}] {1}'.format(title.get('@lang', '').upper() or '', title['$'] or '')
 
 def _format_abstract(abstract):
     if not abstract: return
     lines = to_list(abstract['p'])
-    lines = map(lambda line: line['$'], lines)
-    return u'[{0}] {1}'.format(abstract.get(u'@lang', u'').upper() or u'', '\n'.join(lines))
+    lines = [line['$'] for line in lines]
+    return '[{0}] {1}'.format(abstract.get('@lang', '').upper() or '', '\n'.join(lines))
 
 def _mogrify_parties(partylist, name):
     results = []
@@ -1307,9 +1307,9 @@ def _mogrify_parties(partylist, name):
         parties[key][party['@data-format']] = party[name]['name']['$']
 
     for key in sorted(parties.keys()):
-        name_epodoc = parties[key]['epodoc'].replace(u'\u2002', u' ')
+        name_epodoc = parties[key]['epodoc'].replace('\u2002', ' ')
         name_original = parties[key]['original']
-        entry = u'{0}; {1}'.format(name_epodoc, name_original)
+        entry = '{0}; {1}'.format(name_epodoc, name_original)
         results.append(entry)
 
     return results
@@ -1338,13 +1338,13 @@ def _result_list_compact(response):
 
         try:
             titles = to_list(pointer_invention_title.resolve(result))
-            titles = map(_format_title, titles)
+            titles = list(map(_format_title, titles))
         except JsonPointerException:
             titles = None
 
         try:
             abstracts = to_list(pointer_abstract.resolve(result))
-            abstracts = map(_format_abstract, abstracts)
+            abstracts = list(map(_format_abstract, abstracts))
         except JsonPointerException:
             abstracts = None
 
@@ -1382,10 +1382,10 @@ def _summarize_metrics(payload, kind):
     except KeyError:
         return 'error while computing value'
 
-    total_response_size_entries = filter(lambda item: item['name'] == kind, metrics)[0]['values']
+    total_response_size_entries = [item for item in metrics if item['name'] == kind][0]['values']
     #print total_response_size_entries
 
-    total_response_sizes = map(lambda item: float(item['value']), total_response_size_entries)
+    total_response_sizes = [float(item['value']) for item in total_response_size_entries]
     #print total_response_sizes
 
     total = sum(total_response_sizes)
@@ -1421,6 +1421,6 @@ def ops_service_usage(date_begin, date_end):
 
 if __name__ == '__main__':  # pragma: nocover
     data = ops_service_usage('06/11/2014', '09/12/2014')
-    print 'Time range:    {0}'.format(data['time-range'])
-    print 'Response size: {0}G'.format(data['response-size'] / float(10**9))
-    print 'Message count: {0}'.format(data['message-count'])
+    print('Time range:    {0}'.format(data['time-range']))
+    print('Response size: {0}G'.format(data['response-size'] / float(10**9)))
+    print('Message count: {0}'.format(data['message-count']))
diff --git a/patzilla/access/epo/ops/client.py b/patzilla/access/epo/ops/client.py
index a0037443..75070fd4 100644
--- a/patzilla/access/epo/ops/client.py
+++ b/patzilla/access/epo/ops/client.py
@@ -7,7 +7,7 @@
 from mock import mock
 from pyramid.httpexceptions import HTTPUnauthorized
 from pyramid.threadlocal import get_current_registry
-from zope.interface.declarations import implements
+from zope.interface import implementer
 from zope.interface.interface import Interface
 from zope.interface.interfaces import ComponentLookupError
 
@@ -38,6 +38,8 @@ def from_settings(datasource_settings):
 
     @staticmethod
     def from_environment():
+        if not os.environ["OPS_API_CONSUMER_KEY"] or not os.environ["OPS_API_CONSUMER_SECRET"]:
+            raise KeyError("OPS_API_CONSUMER_KEY or OPS_API_CONSUMER_SECRET is empty")
         return {
             "consumer_key": os.environ["OPS_API_CONSUMER_KEY"],
             "consumer_secret": os.environ["OPS_API_CONSUMER_SECRET"],
@@ -72,14 +74,12 @@ def attach_ops_client(event):
 class IOpsClientPool(Interface):
     pass
 
-
+@implementer(IOpsClientPool)
 class OpsClientPool(object):
     """
     EPO/OPS client pool as Pyramid utility implementation.
     """
 
-    implements(IOpsClientPool)
-
     def __init__(self):
         logger.info("Creating upstream client pool for EPO/OPS")
         self.clients = {}
diff --git a/patzilla/access/epo/ops/commands.py b/patzilla/access/epo/ops/commands.py
index cd94aa02..faab8cb8 100644
--- a/patzilla/access/epo/ops/commands.py
+++ b/patzilla/access/epo/ops/commands.py
@@ -13,6 +13,7 @@
     export OPS_API_CONSUMER_SECRET=rrXdr5WA7x9tudmP
     patzilla ops search "txt=(wind or solar) and energy"
 
+
 Use configuration file::
 
     export PATZILLA_CONFIG=patzilla/config/development-local.ini
@@ -20,6 +21,7 @@
 """
 import json
 import logging
+import sys
 from datetime import date, timedelta
 
 import click
@@ -132,7 +134,7 @@ def image(ctx, document, page, kind, format):
     Access the OPS image acquisition API, see OPS handbook section 3.1.3.
     """
     payload = get_ops_image(document, page, kind, format)
-    print(payload)
+    sys.stdout.buffer.write(payload)
 
 
 ops_cli.add_command(cmd=usage)
diff --git a/patzilla/access/epo/publicationserver/client.py b/patzilla/access/epo/publicationserver/client.py
index 5e9a38bd..5777e48a 100644
--- a/patzilla/access/epo/publicationserver/client.py
+++ b/patzilla/access/epo/publicationserver/client.py
@@ -25,7 +25,7 @@ def fetch_pdf(document_number):
 
     patent = normalize_patent(document_number, as_dict=True, provider='espacenet')
 
-    url_tpl = u'https://data.epo.org/publication-server/pdf-document?cc=EP&pn={number}&ki={kind}'
+    url_tpl = 'https://data.epo.org/publication-server/pdf-document?cc=EP&pn={number}&ki={kind}'
 
     url = url_tpl.format(**patent)
 
@@ -63,4 +63,4 @@ def fetch_pdf(document_number):
 
 
 if __name__ == '__main__':
-    print fetch_pdf('EP666666A2')
+    print(fetch_pdf('EP666666A2'))
diff --git a/patzilla/access/generic/exceptions.py b/patzilla/access/generic/exceptions.py
index 7e9c4224..6b188cef 100644
--- a/patzilla/access/generic/exceptions.py
+++ b/patzilla/access/generic/exceptions.py
@@ -14,11 +14,11 @@ class GenericAdapterException(Exception):
     def __init__(self, *args, **kwargs):
 
         self.data = None
-        if kwargs.has_key('data'):
+        if 'data' in kwargs:
             self.data = kwargs['data']
 
         self.user_info = ''
-        if kwargs.has_key('user_info'):
+        if 'user_info' in kwargs:
             self.user_info = kwargs['user_info']
 
         super(GenericAdapterException, self).__init__(*args)
@@ -30,11 +30,11 @@ def get_message(self):
             #message_parts.append(ex.user_info)
             message['user'] = cgi.escape(self.user_info)
         if hasattr(self, 'message'):
-            message_parts.append(self.__class__.__name__ + u': ' + u'<pre>{message}</pre>'.format(message=cgi.escape(self.message)))
+            message_parts.append(self.__class__.__name__ + ': ' + '<pre>{message}</pre>'.format(message=cgi.escape(self.message)))
         if hasattr(self, 'details'):
-            message_parts.append(u'<pre>{message}</pre>'.format(message=cgi.escape(self.details)))
+            message_parts.append('<pre>{message}</pre>'.format(message=cgi.escape(self.details)))
 
-        message['details'] = u'<br/>'.join(message_parts)
+        message['details'] = '<br/>'.join(message_parts)
 
         return message
 
diff --git a/patzilla/access/generic/pdf.py b/patzilla/access/generic/pdf.py
index c46ba6e5..8516b01f 100644
--- a/patzilla/access/generic/pdf.py
+++ b/patzilla/access/generic/pdf.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # (c) 2013-2022 The PatZilla Developers
 import logging
-from StringIO import StringIO
+from io import StringIO
 from zipfile import ZipFile, ZipInfo, ZIP_DEFLATED
 
 import attr
@@ -56,7 +56,7 @@ def pdf_universal_real(patent, response):
     if document is None:
         log.error('Locating a document at the domestic office requires '
                   'a decoded document number for "{}"'.format(patent))
-        raise ValueError(u'Unable to decode document number {}'.format(patent))
+        raise ValueError('Unable to decode document number {}'.format(patent))
 
     # 1. If it's an EP document, try European publication server first.
     if response.pdf is None and document.country == 'EP':
@@ -92,7 +92,7 @@ def pdf_universal_real(patent, response):
         try:
             # Skip requests for documents w/o kindcode
             if not document.kind:
-                raise ValueError(u'No kindcode for patent: {}'.format(patent))
+                raise ValueError('No kindcode for patent: {}'.format(patent))
 
             response.pdf = depatisconnect_fetch_pdf(number_normalized)
             response.datasource = 'dpma'
diff --git a/patzilla/access/generic/search.py b/patzilla/access/generic/search.py
index 3077c8be..1c819e45 100644
--- a/patzilla/access/generic/search.py
+++ b/patzilla/access/generic/search.py
@@ -4,7 +4,7 @@
 import logging
 from pprint import pprint
 from collections import defaultdict
-from patzilla.util.data.container import SmartBunch
+from patzilla.util.data.container import SmartMunch
 from patzilla.util.numbers.normalize import normalize_patent
 from patzilla.access.generic.exceptions import SearchException
 
@@ -13,27 +13,27 @@
 class GenericSearchClient(object):
 
     def lm(self, message):
-        message = u'{backend_name}: {message}'.format(message=message, **self.__dict__)
+        message = '{backend_name}: {message}'.format(message=message, **self.__dict__)
         return message
 
     def search_failed(self, message=None, response=None, user_info=None, ex=None, meta=None):
 
         # Compute user info
-        user_info = user_info or u'Search failed with unknown reason, please report this error to us.'
+        user_info = user_info or 'Search failed with unknown reason, please report this error to us.'
         meta = meta or {}
 
         # Compute reason and status
-        message = message or u'unknown'
+        message = message or 'unknown'
         if ex:
-            message = u'{}: {}'.format(ex.__class__.__name__, ex.message)
+            message = '{}: {}'.format(ex.__class__.__name__, ex.message)
 
         # Compute and emit log message
-        log_message = u'{backend_name}: Search failed. message={message}'.format(message=message, **self.__dict__)
+        log_message = '{backend_name}: Search failed. message={message}'.format(message=message, **self.__dict__)
         if meta:
-            log_message += u', meta=' + unicode(meta)
+            log_message += ', meta=' + str(meta)
         if response:
-            status = unicode(response.status_code) + u' ' + response.reason
-            log_message += u', status={status}, response=\n{response}'.format(status=status, response=response.content.decode('utf-8'))
+            status = str(response.status_code) + ' ' + response.reason
+            log_message += ', status={status}, response=\n{response}'.format(status=status, response=response.content.decode('utf-8'))
         log.error(log_message)
 
         # Return exception object
@@ -50,7 +50,7 @@ def crawl(self, constituents, expression, chunksize):
 
         # fetch first chunk (1-chunksize) from upstream
         #first_chunk = self.search(expression, 0, chunksize)
-        first_chunk = self.search_method(expression, SmartBunch({'offset': 0, 'limit': chunksize}))
+        first_chunk = self.search_method(expression, SmartMunch({'offset': 0, 'limit': chunksize}))
         #print first_chunk
 
         #total_count = int(first_chunk['meta'].get('pager', {}).get('totalEntries', 0))
@@ -82,7 +82,7 @@ def crawl(self, constituents, expression, chunksize):
             time.sleep(1)
 
             log.info(self.lm('Crawling from offset {offset}'.format(offset=offset)))
-            chunk = self.search_method(expression, SmartBunch({'offset': offset, 'limit': chunksize}))
+            chunk = self.search_method(expression, SmartMunch({'offset': offset, 'limit': chunksize}))
             chunks.append(chunk)
 
 
@@ -128,7 +128,7 @@ def __init__(self, input, options=None):
 
         # Input data and options
         self.input = input
-        self.options = options and SmartBunch.bunchify(options) or SmartBunch()
+        self.options = options and SmartMunch.munchify(options) or SmartMunch()
 
         # Setup data structures
         self.setup()
@@ -146,13 +146,13 @@ def setup(self):
         self.documents = []
 
         # Metadata information, upstream (raw) and downstream (unified)
-        self.meta = SmartBunch.bunchify({
+        self.meta = SmartMunch.munchify({
             'navigator': {},
             'upstream': {},
         })
 
         # Output information, upstream (raw) and downstream (unified)
-        self.output = SmartBunch.bunchify({
+        self.output = SmartMunch.munchify({
             'meta': {},
             'numbers': [],
             'details': [],
@@ -177,8 +177,8 @@ def read_documents(self):
             if number_normalized:
                 number = number_normalized
 
-            document[u'publication_number'] = number
-            document[u'upstream_provider'] = self.meta.upstream.name
+            document['publication_number'] = number
+            document['upstream_provider'] = self.meta.upstream.name
 
     def render(self):
 
@@ -209,14 +209,14 @@ def remove_family_members(self):
         seen = {}
         removed = []
         removed_map = defaultdict(list)
-        stats = SmartBunch(removed = 0)
+        stats = SmartMunch(removed = 0)
         def family_remover(item):
 
             fam = self.document_to_family_id(item)
 
             # Sanity checks on family id
             # Do not remove documents without valid family id
-            if not fam or fam in [u'0', u'-1']:
+            if not fam or fam in ['0', '-1']:
                 return True
 
             # "Seen" filtering logic
@@ -233,7 +233,7 @@ def family_remover(item):
         # Update metadata and content
 
         # 1. Apply family cleansing filter to main documents response
-        self.documents = filter(family_remover, self.documents)
+        self.documents = list(filter(family_remover, self.documents))
         #print 'removed_map:'; pprint(removed_map)
 
         # 2. Add list of removed family members to output
diff --git a/patzilla/access/google/search.py b/patzilla/access/google/search.py
index a55b81c5..b8888e0c 100644
--- a/patzilla/access/google/search.py
+++ b/patzilla/access/google/search.py
@@ -2,11 +2,13 @@
 # (c) 2014 Andreas Motl, Elmyra UG <andreas.motl@elmyra.de>
 import json
 from pyramid.encode import urlencode
-import re
+# py27 import re
 import sys
 import logging
 import requests
-from BeautifulSoup import BeautifulSoup
+# py27 from BeautifulSoup import BeautifulSoup
+from bs4 import BeautifulSoup
+
 from patzilla.util.expression.keywords import keywords_from_boolean_expression
 from patzilla.util.numbers.normalize import normalize_patent
 
@@ -88,7 +90,7 @@ def tweak_captcha_response(self, body):
         captcha_form['action'] = baseurl + '/' + captcha_form['action']
 
         newbody = str(soup)
-        print newbody
+        print(newbody)
         return newbody
 
     def parse_response(self, body):
@@ -163,7 +165,7 @@ def parse_response(self, body):
             'message': message,
         }
 
-        print payload
+        print(payload)
 
         return payload
 
@@ -226,7 +228,7 @@ def pair_to_term(cls, key, value):
                 value_normalized = normalize_patent(value)
                 if value_normalized:
                     value = value_normalized
-            term = u'{0}:{1}'.format(fieldname, value)
+            term = '{0}:{1}'.format(fieldname, value)
         else:
             term = value
 
@@ -243,7 +245,7 @@ def serialize(self):
         """
         query_params = []
         tbs_params = []
-        for key, value in self.criteria.iteritems():
+        for key, value in self.criteria.items():
             term = self.pair_to_term(key, value)
             if term['parameter'] == 'q':
                 query_params.append(term['term'])
@@ -265,7 +267,7 @@ def serialize(self):
 
     def get_keywords(self):
         keywords = []
-        for key, value in self.criteria.iteritems():
+        for key, value in self.criteria.items():
             keywords += keywords_from_boolean_expression(key, value)
         return keywords
 
@@ -282,4 +284,4 @@ def get_keywords(self):
         #data = google.search('matrix', 19900)
         data = google.search('intitle:matrix', 19900)
 
-    print data
+    print(data)
diff --git a/patzilla/access/ificlaims/api.py b/patzilla/access/ificlaims/api.py
index 7680403f..2c30de9e 100644
--- a/patzilla/access/ificlaims/api.py
+++ b/patzilla/access/ificlaims/api.py
@@ -157,7 +157,7 @@ def ificlaims_download_multi(numberlist, formats):
 
         for format in formats:
 
-            format_parts = format.split(u':')
+            format_parts = format.split(':')
 
             # decode modifiers
             if len(format_parts) == 1:
@@ -235,7 +235,7 @@ def ificlaims_download_single(number, format, options=None):
     try:
         response = ificlaims_download(number, format, options)
 
-    except IFIClaimsException, ex:
+    except IFIClaimsException as ex:
         logger.warn('IFI: IFIClaimsException for number={number}, format={format}, options={options}: {ex}'.format(**locals()))
 
     if response.payload:
diff --git a/patzilla/access/ificlaims/client.py b/patzilla/access/ificlaims/client.py
index db9a7f2a..0febf090 100644
--- a/patzilla/access/ificlaims/client.py
+++ b/patzilla/access/ificlaims/client.py
@@ -16,7 +16,7 @@
 from patzilla.access.generic.exceptions import NoResultsException, GenericAdapterException, SearchException
 from patzilla.access.generic.search import GenericSearchResponse, GenericSearchClient
 from patzilla.access.ificlaims import get_ificlaims_client
-from patzilla.util.data.container import SmartBunch
+from patzilla.util.data.container import SmartMunch
 from patzilla.util.numbers.normalize import normalize_patent
 
 log = logging.getLogger(__name__)
@@ -73,7 +73,7 @@ def search_real(self, query, options=None):
 
         query.setdefault('filter', '')
 
-        options = options or SmartBunch()
+        options = options or SmartMunch()
         options.setdefault('offset', 0)
         options.setdefault('limit', self.pagesize)
 
@@ -141,36 +141,36 @@ def search_real(self, query, options=None):
                     if 'msg' not in upstream_error:
                         upstream_error['msg'] = 'Reason unknown'
 
-                    message = u'Response status code: {code}\n\n{msg}'.format(**upstream_error)
+                    message = 'Response status code: {code}\n\n{msg}'.format(**upstream_error)
 
                     # Enrich "maxClauseCount" message, e.g. raised by {!complexphrase}text:"auto* AND leucht*"~5
-                    if upstream_error["code"] == 500 and u'maxClauseCount is set to' in upstream_error["msg"]:
+                    if upstream_error["code"] == 500 and 'maxClauseCount is set to' in upstream_error["msg"]:
                         raise self.search_failed(
-                            user_info=u'Too many terms in phrase expression, wildcard term prefixes might by too short.',
+                            user_info='Too many terms in phrase expression, wildcard term prefixes might by too short.',
                             message=message,
                             response=response)
 
                     # Enrich "no servers hosting shard" message
                     elif upstream_error["code"] == 503 and \
                         (
-                            u'no servers hosting shard' in upstream_error["msg"] or \
-                            u'No server is available' in upstream_error["msg"]
+                            'no servers hosting shard' in upstream_error["msg"] or \
+                            'No server is available' in upstream_error["msg"]
                         ):
                         raise self.search_failed(
-                            user_info=u'Error while connecting to upstream database. Database might be offline.',
+                            user_info='Error while connecting to upstream database. Database might be offline.',
                             message=message,
                             response=response)
 
                     # Regular traceback
                     elif upstream_error["code"] == 500 and 'trace' in upstream_error:
-                        message = u'Response status code: {code}\n\n{trace}'.format(**upstream_error)
+                        message = 'Response status code: {code}\n\n{trace}'.format(**upstream_error)
                         raise self.search_failed(
-                            user_info=u'Unknown exception at search backend',
+                            user_info='Unknown exception at search backend',
                             message=message,
                             response=response)
 
                     # Enrich "SyntaxError" exception
-                    elif upstream_error["code"] == 400 and u'ParseException' in upstream_error["msg"]:
+                    elif upstream_error["code"] == 400 and 'ParseException' in upstream_error["msg"]:
                         user_info = re.sub(
                             r'.*(Encountered.*at line.*?\.).*',
                             r'SyntaxError, can not parse query expression: \1',
@@ -207,7 +207,7 @@ def search_real(self, query, options=None):
 
                 user_info = None
                 if response_data['message'] == 'JSON error: failed to read response object':
-                    user_info = u'Error while connecting to upstream database. Database might be offline.'
+                    user_info = 'Error while connecting to upstream database. Database might be offline.'
 
                 raise self.search_failed(
                     user_info=user_info,
@@ -237,7 +237,7 @@ def search_real(self, query, options=None):
             message = json.dumps(upstream_error)
 
             raise self.search_failed(
-                user_info=u'Error while connecting to upstream database. Database might be offline.',
+                user_info='Error while connecting to upstream database. Database might be offline.',
                 message=message,
                 response=response)
 
@@ -252,9 +252,10 @@ def text_fetch(self, ucid, format='xml'):
         EP666666A2 => EP0666666A2 (EP0666666A3, EP0666666B1)
         """
 
-        log.info(u"{backend_name}: text_fetch, ucid={ucid}, format={format}; user={username}".format(
+        log.info("{backend_name}: text_fetch, ucid={ucid}, format={format}; user={username}".format(
             ucid=ucid, format=format, **self.__dict__))
 
+
         starttime = timeit.default_timer()
 
         if not self.token or self.stale:
@@ -288,7 +289,7 @@ def text_fetch(self, ucid, format='xml'):
     @cache_region('longer')
     def attachment_list(self, ucid):
 
-        log.info(u"{backend_name}: attachment_list, ucid={ucid}; user={username}".format(ucid=ucid, **self.__dict__))
+        log.info("{backend_name}: attachment_list, ucid={ucid}; user={username}".format(ucid=ucid, **self.__dict__))
 
         if not self.token or self.stale:
             self.login()
@@ -310,14 +311,14 @@ def attachment_list(self, ucid):
             data = json.loads(response.content)
             return data
         else:
-            log.error(u"{backend_name}: attachment_list, ucid={ucid}, status={status}, response={response}".format(
+            log.error("{backend_name}: attachment_list, ucid={ucid}, status={status}, response={response}".format(
                 ucid=ucid, status=response.status_code, response=response.content , **self.__dict__))
 
 
     @cache_region('longer')
     def attachment_fetch(self, path):
 
-        log.info(u"{backend_name}: attachment_fetch, path={path}; user={username}".format(path=path, **self.__dict__))
+        log.info("{backend_name}: attachment_fetch, path={path}; user={username}".format(path=path, **self.__dict__))
 
         if not self.token or self.stale:
             self.login()
@@ -341,18 +342,19 @@ def attachment_fetch(self, path):
             return response.content
 
         else:
-            log.error(u"{backend_name}: attachment_fetch, path={path}, status={status}, response={response}".format(
+            log.error("{backend_name}: attachment_fetch, path={path}, status={status}, response={response}".format(
                 path=path, status=response.status_code, response=response.content , **self.__dict__))
 
 
     def pdf_fetch(self, ucid):
 
-        log.info(u"{backend_name}: pdf_fetch, ucid={ucid}; user={username}".format(ucid=ucid, **self.__dict__))
+        log.info("{backend_name}: pdf_fetch, ucid={ucid}; user={username}".format(ucid=ucid, **self.__dict__))
 
         attachments_response = self.attachment_list(ucid)
         if not attachments_response:
             return
 
+
         #print 'attachments_response:'
         #pprint(attachments_response)
 
@@ -435,7 +437,7 @@ def tif_attachments(self, ucid):
             """
 
             # filter tif references only
-            tif_attachments = filter(lambda attachment: attachment['media'] in ['image/tiff', 'image/jpeg'], attachments)
+            tif_attachments = [attachment for attachment in attachments if attachment['media'] in ['image/tiff', 'image/jpeg']]
             #print 'tif_attachments:'
             #pprint(tif_attachments)
             return tif_attachments
@@ -443,7 +445,7 @@ def tif_attachments(self, ucid):
 
     def tif_fetch(self, ucid, seq=1):
 
-        log.info(u"{backend_name}: tif_fetch, ucid={ucid}, seq={seq}; user={username}".format(ucid=ucid, seq=seq, **self.__dict__))
+        log.info("{backend_name}: tif_fetch, ucid={ucid}, seq={seq}; user={username}".format(ucid=ucid, seq=seq, **self.__dict__))
 
         tif_attachments = self.tif_attachments(ucid)
 
@@ -464,7 +466,7 @@ def tif_fetch(self, ucid, seq=1):
 
     @cache_region('longer')
     def png_fetch(self, ucid, seq=1):
-        log.info(u"{backend_name}: png_fetch, ucid={ucid}, seq={seq}; user={username}".format(ucid=ucid, seq=seq, **self.__dict__))
+        log.info("{backend_name}: png_fetch, ucid={ucid}, seq={seq}; user={username}".format(ucid=ucid, seq=seq, **self.__dict__))
         tif = self.tif_fetch(ucid, seq)
         if tif:
             png = to_png(tif)
@@ -520,22 +522,22 @@ def read(self):
             'name': 'ifi',
             'time': self.input['time'],
             'status': self.input['status'],
-            'params': SmartBunch.bunchify(self.input['content']['responseHeader']['params']),
-            'pager': SmartBunch.bunchify(self.input['content']['responseHeader'].get('pager', {})),
+            'params': SmartMunch.munchify(self.input['content']['responseHeader']['params']),
+            'pager': SmartMunch.munchify(self.input['content']['responseHeader'].get('pager', {})),
         })
 
         self.meta.navigator.count_total = int(self.meta.upstream.pager.totalEntries)
         self.meta.navigator.count_page  = int(self.meta.upstream.pager.entriesOnThisPage)
         self.meta.navigator.offset      = int(self.meta.upstream.params.start)
         self.meta.navigator.limit       = int(self.meta.upstream.params.rows)
-        self.meta.navigator.postprocess = SmartBunch()
+        self.meta.navigator.postprocess = SmartMunch()
 
         # Read content
         self.documents = self.input['content']['response']['docs']
         self.read_documents()
 
     def document_to_number(self, document):
-        ucid = document[u'ucid']
+        ucid = document['ucid']
         cc, docno, kindcode = ucid.split('-')
         number = cc + docno + kindcode
         number_normalized = normalize_patent(number)
@@ -548,7 +550,7 @@ def document_to_family_id(self, document):
 
 
 def ificlaims_client(options=None):
-    options = options or SmartBunch()
+    options = options or SmartMunch()
     if 'vendor' in options and options.vendor == 'serviva':
         client = get_serviva_client()
     else:
@@ -576,7 +578,7 @@ def ificlaims_fetch(resource, format, options=None):
 @cache_region('search')
 def ificlaims_search(query, options=None):
 
-    options = options or SmartBunch()
+    options = options or SmartMunch()
 
     client = ificlaims_client(options=options)
     try:
diff --git a/patzilla/access/ificlaims/clientpool.py b/patzilla/access/ificlaims/clientpool.py
index 1e0fc64e..a926ad16 100644
--- a/patzilla/access/ificlaims/clientpool.py
+++ b/patzilla/access/ificlaims/clientpool.py
@@ -4,7 +4,7 @@
 import os
 
 from pyramid.httpexceptions import HTTPUnauthorized
-from zope.interface.declarations import implements
+from zope.interface import implementer
 from zope.interface.interface import Interface
 
 from patzilla.access.generic.credentials import AbstractCredentialsGetter, DatasourceCredentialsManager
@@ -46,6 +46,8 @@ def from_settings(datasource_settings):
 
     @staticmethod
     def from_environment():
+        if not os.environ["IFICLAIMS_API_USERNAME"] or not os.environ["IFICLAIMS_API_PASSWORD"]:
+            raise KeyError("IFICLAIMS_API_USERNAME or IFICLAIMS_API_PASSWORD is empty")
         return {
             "api_username": os.environ["IFICLAIMS_API_USERNAME"],
             "api_password": os.environ["IFICLAIMS_API_PASSWORD"],
@@ -81,12 +83,12 @@ class IIFIClaimsClientPool(Interface):
     pass
 
 
+@implementer(IIFIClaimsClientPool)
 class IFIClaimsClientPool(object):
     """
     IFI CLAIMS client pool as Pyramid utility implementation.
     """
 
-    implements(IIFIClaimsClientPool)
 
     def __init__(self, api_uri, api_uri_json):
         logger.info("Creating upstream client pool for IFI CLAIMS")
diff --git a/patzilla/access/ificlaims/commands.py b/patzilla/access/ificlaims/commands.py
index d44f2d56..1fe7f7fe 100644
--- a/patzilla/access/ificlaims/commands.py
+++ b/patzilla/access/ificlaims/commands.py
@@ -33,7 +33,7 @@
 from patzilla.boot.cache import configure_cache_backend
 from patzilla.boot.config import BootConfiguration
 from patzilla.util.config import get_configfile_from_commandline
-from patzilla.util.data.container import SmartBunch, jd
+from patzilla.util.data.container import SmartMunch, jd
 from patzilla.boot.framework import pyramid_setup
 
 
@@ -79,7 +79,7 @@ def search(ctx, expression, request_json):
 
     # Invoke API and output result.
     logger.warning("Only the first 100 hits will be displayed. The CLI currently does not employ paging.")
-    results = client.search(SmartBunch({'expression': expression}), SmartBunch({'offset': 0, 'limit': 100}))
+    results = client.search(SmartMunch({'expression': expression}), SmartMunch({'offset': 0, 'limit': 100}))
     print(jd(results))
 
 
@@ -95,11 +95,12 @@ def make_request(client):
     #results = client.search('pa:siemens OR pa:bosch', 0, 10)
     #results = client.search('pa:(siemens OR bosch)', 0, 10)
     #results = client.search('text:"solar energy"', 0, 10)
-    results = client.search(SmartBunch({'expression': 'text:solar energy'}), SmartBunch({'offset': 0, 'limit': 10}))
-    #results = client.search(SmartBunch({'expression': '{!complexphrase inOrder=true}"siemen* *haus"'}), SmartBunch({'offset': 0, 'limit': 10}))
+    results = client.search(SmartMunch({'expression': 'text:solar energy'}), SmartMunch({'offset': 0, 'limit': 10}))
+    #results = client.search(SmartMunch({'expression': '{!complexphrase inOrder=true}"siemen* *haus"'}), SmartMunch({'offset': 0, 'limit': 10}))
     #results = client.search(u'text:抑血管生成素的药物用途', 0, 10)
     #results = client.search(u'text:放射線を照射する放射線源と', 0, 10)
-    #results = client.search(SmartBunch({'expression': 'pnctry:(de OR ep OR wo OR cn OR jp OR tw) AND pa:"taiwan paiho" AND pd:[20170101 TO 20170731]'}), SmartBunch({'offset': 0, 'limit': 50}))
+    #results = client.search(SmartMunch({'expression': 'pnctry:(de OR ep OR wo OR cn OR jp OR tw) AND pa:"taiwan paiho" AND pd:[20170101 TO 20170731]'}), SmartMunch({'offset': 0, 'limit': 50}))
+
 
     #results = client.text_fetch('US-20100077592-A1')
     #results = client.text_fetch('CN-1055497-A')
diff --git a/patzilla/access/ificlaims/expression.py b/patzilla/access/ificlaims/expression.py
index 9496b698..64a8a704 100644
--- a/patzilla/access/ificlaims/expression.py
+++ b/patzilla/access/ificlaims/expression.py
@@ -22,7 +22,7 @@
 class IFIClaimsGrammar(CQLGrammar):
     def preconfigure(self):
         CQLGrammar.preconfigure(self)
-        self.cmp_single = u':'.split()
+        self.cmp_single = ':'.split()
 
 
 class IFIClaimsParser(object):
@@ -60,8 +60,8 @@ def trim_complexphrase(self):
         after:                  text:((parallel* AND schalt*) AND (antrieb* AND stufe*))
         """
         #print >>sys.stderr, 'expression-before:', self.expression
-        self.expression = re.sub(u'"(.+?)"~\d+', u'(\\1)', self.expression)
-        self.expression = self.expression.replace(u'{!complexphrase}', '')
+        self.expression = re.sub('"(.+?)"~\d+', '(\\1)', self.expression)
+        self.expression = self.expression.replace('{!complexphrase}', '')
         #print >>sys.stderr, 'expression-after :', self.expression
 
     @property
@@ -192,7 +192,7 @@ def pair_to_solr(cls, key, value, modifiers=None):
             return
 
         expression = None
-        format = u'{0}:{1}'
+        format = '{0}:{1}'
 
 
         # ------------------------------------------
@@ -230,7 +230,7 @@ def pair_to_solr(cls, key, value, modifiers=None):
                 # within 2009-08-20,2011-03-03
                 if 'within' in value:
                     within_dates = parse_date_within(value)
-                    elements_are_years = all([len(value) == 4 and value.isdigit() for value in within_dates.values()])
+                    elements_are_years = all([len(value) == 4 and value.isdigit() for value in list(within_dates.values())])
                     if elements_are_years:
                         fieldname = 'pdyear'
 
@@ -258,12 +258,12 @@ def pair_to_solr(cls, key, value, modifiers=None):
 
             except Exception as ex:
                 message = 'IFI CLAIMS query: Invalid date or range expression "{0}". Reason: {1}.'.format(value, ex)
-                logger.warn(message + '\nException was:\n{0}'.format(_exception_traceback()))
+                logger.warning(message + '\nException was:\n{0}'.format(_exception_traceback()))
                 return {'error': True, 'message': message}
 
         elif key == 'inventor' or key == 'applicant':
             if not has_booleans(value) and should_be_quoted(value):
-                value = u'"{0}"'.format(value)
+                value = '"{0}"'.format(value)
 
         elif key == 'class':
 
@@ -277,7 +277,7 @@ def pair_to_solr(cls, key, value, modifiers=None):
 
                 # Put value into parenthesis, to properly capture expressions
                 if value:
-                    value = u'({value})'.format(value=value)
+                    value = '({value})'.format(value=value)
 
                 # Parse value as simple query expression
                 query_object = CQL(cql=value)
@@ -297,7 +297,7 @@ def pair_to_solr(cls, key, value, modifiers=None):
         # ------------------------------------------
         if key in ['fulltext', 'inventor', 'applicant', 'country', 'citation']:
             if has_booleans(value) and not should_be_quoted(value) and not '{!complexphrase' in value:
-                value = u'({0})'.format(value)
+                value = '({0})'.format(value)
 
         # ------------------------------------------
         #   expression formatter
@@ -368,15 +368,15 @@ def triple_callback(token, index, binop, term):
 
 def format_expression(format, fieldname, value):
     expression = None
-    if type(fieldname) in types.StringTypes:
+    if type(fieldname) in (str,):
         expression = format.format(fieldname, value)
-    elif type(fieldname) is types.ListType:
+    elif type(fieldname) is list:
         subexpressions = []
         for fieldname in fieldname:
             subexpressions.append(format.format(fieldname, value))
         expression = ' or '.join(subexpressions)
         # surround with parentheses
-        expression = u'({0})'.format(expression)
+        expression = '({0})'.format(expression)
     return expression
 
 def ifi_convert_class(value):
@@ -406,5 +406,5 @@ def should_be_quoted(value):
 
 
 if __name__ == '__main__':
-    print IFIClaimsParser('{!complexphrase}text:"(aussto* OR eject* OR pusher*) AND (verriegel* OR lock* OR sperr*)"~6').keywords
-    print IFIClaimsParser('{!complexphrase}text:"parallel* AND schalt*"~6 AND ((ic:F16H006104 OR cpc:F16H006104))').keywords
+    print(IFIClaimsParser('{!complexphrase}text:"(aussto* OR eject* OR pusher*) AND (verriegel* OR lock* OR sperr*)"~6').keywords)
+    print(IFIClaimsParser('{!complexphrase}text:"parallel* AND schalt*"~6 AND ((ic:F16H006104 OR cpc:F16H006104))').keywords)
diff --git a/patzilla/access/ificlaims/expression.rst b/patzilla/access/ificlaims/expression.rst
index 2162ee87..61c78a07 100644
--- a/patzilla/access/ificlaims/expression.rst
+++ b/patzilla/access/ificlaims/expression.rst
@@ -20,30 +20,30 @@ Empty query
 IPC/CPC
 =======
 >>> IFIClaimsParser('H01F7/00').dumps()
-u'H01F7/00'
+'H01F7/00'
 
 # Rewrite all patent classifications from IFI format to OPS format
 >>> IFIClaimsParser('ic:G01F000184').parse().rewrite_classes_ops().dumps()
-u'ic : G01F1/84'
+'ic : G01F1/84'
 
 >>> IFIClaimsParser('ic:G01F000184').keywords
-[u'G01F1/84']
+['G01F1/84']
 
 >>> IFIClaimsExpression.pair_to_solr('class', 'H04L12/433 or H04L12/24')
-{'query': u'((ic:H04L0012433 OR cpc:H04L0012433) OR (ic:H04L001224 OR cpc:H04L001224))'}
+{'query': '((ic:H04L0012433 OR cpc:H04L0012433) OR (ic:H04L001224 OR cpc:H04L001224))'}
 
 >>> IFIClaimsExpression.pair_to_solr('class', 'H01F7/00 or (H01F7/02 and H02K7/1876)')
-{'query': u'((ic:H01F000700 OR cpc:H01F000700) OR ((ic:H01F000702 OR cpc:H01F000702) AND (ic:H02K00071876 OR cpc:H02K00071876)))'}
+{'query': '((ic:H01F000700 OR cpc:H01F000700) OR ((ic:H01F000702 OR cpc:H01F000702) AND (ic:H02K00071876 OR cpc:H02K00071876)))'}
 
 >>> IFIClaimsExpression.pair_to_solr('class', 'H01F7/00 not (H01F7/02 or H02K7/1876)')
-{'query': u'((ic:H01F000700 OR cpc:H01F000700) NOT ((ic:H01F000702 OR cpc:H01F000702) OR (ic:H02K00071876 OR cpc:H02K00071876)))'}
+{'query': '((ic:H01F000700 OR cpc:H01F000700) NOT ((ic:H01F000702 OR cpc:H01F000702) OR (ic:H02K00071876 OR cpc:H02K00071876)))'}
 
 
 Publication date
 ================
 
 >>> IFIClaimsExpression.pair_to_solr('pubdate', 'foobar')
-{'message': 'IFI CLAIMS query: Invalid date or range expression "foobar". Reason: foobar.', 'error': True}
+{'error': True, 'message': 'IFI CLAIMS query: Invalid date or range expression "foobar". Reason: foobar.'}
 
 
 *********
@@ -54,39 +54,39 @@ Simple expressions
 ==================
 
 >>> IFIClaimsParser('ttl:bildschirm').keywords
-[u'bildschirm']
+['bildschirm']
 
 >>> IFIClaimsExpression.pair_to_solr('fulltext', 'bildschirm')
-{'query': u'text:bildschirm'}
+{'query': 'text:bildschirm'}
 
 
 >>> IFIClaimsParser('ttl:bildschirm or ab:fahrzeug').keywords
-[u'bildschirm', u'fahrzeug']
+['bildschirm', 'fahrzeug']
 
 >>> IFIClaimsExpression.pair_to_solr('fulltext', 'bildschirm or fahrzeug')
-{'query': u'text:(bildschirm OR fahrzeug)'}
+{'query': 'text:(bildschirm OR fahrzeug)'}
 
 
 >>> IFIClaimsParser('ttl:bildschirm and ab:(fahrzeug or pkw)').keywords
-[u'bildschirm', u'fahrzeug', u'pkw']
+['bildschirm', 'fahrzeug', 'pkw']
 
 >>> IFIClaimsExpression.pair_to_solr('fulltext', 'bildschirm and (fahrzeug or pkw)')
-{'query': u'text:(bildschirm AND (fahrzeug OR pkw))'}
+{'query': 'text:(bildschirm AND (fahrzeug OR pkw))'}
 
 
 >>> IFIClaimsParser('ttl:bildschirm and ab:(fahrzeug or pkw not lkw)').keywords
-[u'bildschirm', u'fahrzeug', u'pkw', u'lkw']
+['bildschirm', 'fahrzeug', 'pkw', 'lkw']
 
 >>> IFIClaimsExpression.pair_to_solr('fulltext', 'bildschirm and (fahrzeug or pkw not lkw)')
-{'query': u'text:(bildschirm AND (fahrzeug OR pkw NOT lkw))'}
+{'query': 'text:(bildschirm AND (fahrzeug OR pkw NOT lkw))'}
 
 
 >>> IFIClaimsParser('ab:fahrzeug or ab:pkw').keywords
-[u'fahrzeug', u'pkw']
+['fahrzeug', 'pkw']
 
 
 >>> IFIClaimsParser('ab:fahrzeug not ttl:pkw').keywords
-[u'fahrzeug', u'pkw']
+['fahrzeug', 'pkw']
 
 
 
@@ -96,22 +96,22 @@ Expressions with proximity operators
 Queries based on the proximity of words to each other in a document.
 
 >>> IFIClaimsParser('text:((aussto* OR eject* OR pusher*) AND (verriegel* OR lock* OR sperr*))').keywords
-[u'aussto', u'eject', u'pusher', u'verriegel', u'lock', u'sperr']
+['aussto', 'eject', 'pusher', 'verriegel', 'lock', 'sperr']
 
 >>> IFIClaimsParser('{!complexphrase}text:"(aussto* OR eject* OR pusher*) AND (verriegel* OR lock* OR sperr*)"~6').keywords
-[u'aussto', u'eject', u'pusher', u'verriegel', u'lock', u'sperr']
+['aussto', 'eject', 'pusher', 'verriegel', 'lock', 'sperr']
 
 >>> IFIClaimsExpression.pair_to_solr('fulltext', '{!complexphrase}text:"(aussto* OR eject* OR pusher*) AND (verriegel* OR lock* OR sperr*)"~6')
 {'query': '{!complexphrase}text:"(aussto* OR eject* OR pusher*) AND (verriegel* OR lock* OR sperr*)"~6'}
 
 >>> IFIClaimsParser('{!complexphrase}text:"parallel* AND schalt*"~6 AND ((ic:F16H006104 OR cpc:F16H006104))').keywords
-[u'parallel', u'schalt', u'F16H61/04']
+['parallel', 'schalt', 'F16H61/04']
 
 >>> IFIClaimsParser('((ic:F16H006104 OR cpc:F16H006104)) AND {!complexphrase}text:"parallel* AND schalt*"~6').keywords
-[u'F16H61/04', u'parallel', u'schalt']
+['F16H61/04', 'parallel', 'schalt']
 
 >>> IFIClaimsParser('{!complexphrase}text:("parallel* AND schalt*"~6 AND "antrieb* AND stufe*"~3)').keywords
-[u'parallel', u'schalt', u'antrieb', u'stufe']
+['parallel', 'schalt', 'antrieb', 'stufe']
 
 
 
@@ -122,17 +122,17 @@ Queries without proper fieldnames like ab=, ti=, bi=, etc. on the left side of t
 
 
 >>> IFIClaimsParser('bildschirm').dumps()
-u'bildschirm'
+'bildschirm'
 
 >>> IFIClaimsExpression.pair_to_solr('fulltext', 'bildschirm')
-{'query': u'text:bildschirm'}
+{'query': 'text:bildschirm'}
 
 
 >>> IFIClaimsParser('bildschirm and fahrzeug').dumps()
-u'bildschirm and fahrzeug'
+'bildschirm and fahrzeug'
 
 >>> IFIClaimsExpression.pair_to_solr('fulltext', 'bildschirm and fahrzeug')
-{'query': u'text:(bildschirm AND fahrzeug)'}
+{'query': 'text:(bildschirm AND fahrzeug)'}
 
 
 
@@ -140,22 +140,22 @@ Expressions containing quoted words
 ===================================
 
 >>> IFIClaimsParser('"bildschirm"').dumps()
-u'"bildschirm"'
+'"bildschirm"'
 
 >>> IFIClaimsParser('"bildschirm"').keywords
 []
 
 >>> IFIClaimsExpression.pair_to_solr('fulltext', '"bildschirm"')
-{'query': u'text:"bildschirm"'}
+{'query': 'text:"bildschirm"'}
 
 >>> IFIClaimsParser('ab:"bildschirm"').dumps()
-u'ab : "bildschirm"'
+'ab : "bildschirm"'
 
 >>> IFIClaimsParser('ab:"bildschirm"').keywords
-[u'bildschirm']
+['bildschirm']
 
 >>> IFIClaimsParser('text:(("aussto*" OR "eject*" OR pusher*) AND (verriegel* OR lock* OR sperr*))').keywords
-[u'aussto', u'eject', u'pusher', u'verriegel', u'lock', u'sperr']
+['aussto', 'eject', 'pusher', 'verriegel', 'lock', 'sperr']
 
 
 
@@ -163,19 +163,19 @@ Keyword extraction
 ==================
 
 >>> IFIClaimsParser(IFIClaimsExpression.pair_to_solr('class', 'H01F7/00')['query']).keywords
-[u'H01F7/00']
+['H01F7/00']
 
 >>> IFIClaimsParser(IFIClaimsExpression.pair_to_solr('class', 'H01F7/00 not (H01F7/02 or H02K7/1876)')['query']).keywords
-[u'H01F7/00', u'H01F7/02', u'H02K7/1876']
+['H01F7/00', 'H01F7/02', 'H02K7/1876']
 
 >>> IFIClaimsParser(IFIClaimsExpression.pair_to_solr('fulltext', 'bildschirm')['query']).keywords
-[u'bildschirm']
+['bildschirm']
 
 >>> IFIClaimsParser(IFIClaimsExpression.pair_to_solr('fulltext', '"bildschirm"')['query']).keywords
-[u'bildschirm']
+['bildschirm']
 
 >>> IFIClaimsParser(IFIClaimsExpression.pair_to_solr('fulltext', 'ttl:bildschirm OR ab:(fahrzeug OR pkw)')['query']).keywords
-[u'bildschirm', u'fahrzeug', u'pkw']
+['bildschirm', 'fahrzeug', 'pkw']
 
 
 
@@ -185,18 +185,18 @@ From the wild
 Umlauts
 -------
 
->>> IFIClaimsParser(u'tac:((*messschieber* OR *meßschieber*) AND *digital* )').dumps()
-u'((tac : *messschieber* or tac : *me\xdfschieber*) and tac : *digital*)'
+>>> IFIClaimsParser('tac:((*messschieber* OR *meßschieber*) AND *digital* )').dumps()
+'((tac : *messschieber* or tac : *me\xdfschieber*) and tac : *digital*)'
 
->>> IFIClaimsParser(u'tac:((*messschieber* OR *meßschieber*) AND *digital* )').keywords
-[u'messschieber', u'me\xdfschieber', u'digital']
+>>> IFIClaimsParser('tac:((*messschieber* OR *meßschieber*) AND *digital* )').keywords
+['messschieber', 'me\xdfschieber', 'digital']
 
 
 More
 ----
 
->>> IFIClaimsParser(u'ttl:(energy and water) or ab:(waves or Tide) and clm:"90°"').keywords
-[u'energy', u'water', u'waves', u'Tide', u'90\xb0']
+>>> IFIClaimsParser('ttl:(energy and water) or ab:(waves or Tide) and clm:"90°"').keywords
+['energy', 'water', 'waves', 'Tide', '90\xb0']
 
->>> IFIClaimsParser(u'text:(((bremsgefühl* or pedalgefühl) and (*simulator or simul*)) and (separ* or getrennt* or entkoppel* or entkoppl* or decoupl*) and (eigenständig* or independent* or autonom*))').keywords
-[u'bremsgef\xfchl', u'pedalgef\xfchl', u'simulator', u'simul', u'separ', u'getrennt', u'entkoppel', u'entkoppl', u'decoupl', u'eigenst\xe4ndig', u'independent', u'autonom']
+>>> IFIClaimsParser('text:(((bremsgefühl* or pedalgefühl) and (*simulator or simul*)) and (separ* or getrennt* or entkoppel* or entkoppl* or decoupl*) and (eigenständig* or independent* or autonom*))').keywords
+['bremsgef\xfchl', 'pedalgef\xfchl', 'simulator', 'simul', 'separ', 'getrennt', 'entkoppel', 'entkoppl', 'decoupl', 'eigenst\xe4ndig', 'independent', 'autonom']
diff --git a/patzilla/access/office.py b/patzilla/access/office.py
index 43531d75..da08fb70 100644
--- a/patzilla/access/office.py
+++ b/patzilla/access/office.py
@@ -76,5 +76,5 @@ def jump_office(request):
             else:
                 return url
 
-    return HTTPNotFound(u'Could not locate document "{document_number}" at {office}/{service}.'.format(
+    return HTTPNotFound('Could not locate document "{document_number}" at {office}/{service}.'.format(
         document_number=document_number, office=office, service=service))
diff --git a/patzilla/access/sip/client.py b/patzilla/access/sip/client.py
index 9eba41bb..11de635d 100644
--- a/patzilla/access/sip/client.py
+++ b/patzilla/access/sip/client.py
@@ -9,7 +9,7 @@
 from patzilla.access.generic.exceptions import NoResultsException, GenericAdapterException
 from patzilla.access.generic.search import GenericSearchResponse, GenericSearchClient
 from patzilla.access.sip import get_sip_client
-from patzilla.util.data.container import SmartBunch
+from patzilla.util.data.container import SmartMunch
 
 """
 
@@ -27,9 +27,9 @@ class SipException(GenericAdapterException):
     def __init__(self, *args, **kwargs):
         self.sip_info = ''
         super(SipException, self).__init__(*args)
-        if kwargs.has_key('sip_info'):
+        if 'sip_info' in kwargs:
             self.sip_info = kwargs['sip_info']
-        if kwargs.has_key('sip_response'):
+        if 'sip_response' in kwargs:
             self.sip_info = kwargs['sip_response'].get_childvalue('Info')
         if self.sip_info:
             self.user_info = self.sip_info
@@ -98,7 +98,7 @@ def logout(self):
 
     def search(self, expression, options=None):
 
-        options = options or SmartBunch()
+        options = options or SmartMunch()
 
         options.setdefault('offset', 0)
         options.setdefault('limit', self.pagesize)
@@ -106,7 +106,7 @@ def search(self, expression, options=None):
         offset = options.offset
         limit  = options.limit
 
-        log.info(u"{backend_name}: searching documents, expression='{0}', offset={1}, limit={2}".format(
+        log.info("{backend_name}: searching documents, expression='{0}', offset={1}, limit={2}".format(
             expression, offset, limit, **self.__dict__))
 
         if not self.sessionid or self.stale:
@@ -116,11 +116,11 @@ def search(self, expression, options=None):
         try:
             response = requests.post(self.uri + '/search/new', data={'session': self.sessionid, 'searchtree': expression})
         except (ConnectionError, ConnectTimeout) as ex:
-            log.error(u'SIP search for user "{username}" at "{uri}" failed. Reason: {0} {1}.'.format(
+            log.error('SIP search for user "{username}" at "{uri}" failed. Reason: {0} {1}.'.format(
                 ex.__class__, ex.message, username=self.username, uri=self.uri))
             self.logout()
             raise SearchException(ex.message,
-                sip_info=u'Error or timeout while connecting to upstream database. Database might be offline.')
+                sip_info='Error or timeout while connecting to upstream database. Database might be offline.')
 
         # Process search response
         if response.status_code == 200:
@@ -129,7 +129,7 @@ def search(self, expression, options=None):
                 search_response = self._search_parse_xml(response.content)
 
                 if search_response['success'] == 'false':
-                    raise SearchException(u'Search failed', sip_response=search_response['response'])
+                    raise SearchException('Search failed', sip_response=search_response['response'])
 
                 if 'ResultSetId' in search_response['data']:
 
@@ -145,7 +145,7 @@ def search(self, expression, options=None):
                     #print "SIP search results:", search_results
 
                     duration = timeit.default_timer() - starttime
-                    log.info(u'Search succeeded. duration={0}s, search_info={1}'.format(round(duration, 1), search_info))
+                    log.info('Search succeeded. duration={0}s, search_info={1}'.format(round(duration, 1), search_info))
 
                     upstream_response = {
                         'info': search_info,
@@ -159,33 +159,33 @@ def search(self, expression, options=None):
                     duration = round(duration, 1)
 
                     # TODO: Unify between SIP and IFI CLAIMS
-                    log.info(u'{backend_name}: Search succeeded. duration={duration}s, meta=\n{meta}'.format(
+                    log.info('{backend_name}: Search succeeded. duration={duration}s, meta=\n{meta}'.format(
                         duration=duration, meta=result['meta'].prettify(), **self.__dict__))
 
                     if not result['numbers']:
-                        log.warn(u'{backend_name} search from "{user}" for "{expression}" had empty results.'.format(
+                        log.warn('{backend_name} search from "{user}" for "{expression}" had empty results.'.format(
                             user=self.username, expression=expression, **self.__dict__
                         ))
 
                     return result
 
                 else:
-                    message = u'Search failed. Reason: Upstream response lacks valid ResultSetId. content={0}'.format(response.text)
-                    raise SearchException(message, sip_info=u'Search failed. Search response could not be parsed.')
+                    message = 'Search failed. Reason: Upstream response lacks valid ResultSetId. content={0}'.format(response.text)
+                    raise SearchException(message, sip_info='Search failed. Search response could not be parsed.')
 
             except Exception as ex:
-                log.error(u'Search failed. {name}: {message}. expression={expression}, response={response}'.format(
+                log.error('Search failed. {name}: {message}. expression={expression}, response={response}'.format(
                     name=ex.__class__.__name__, message=ex.message, response=response.text, expression=expression))
                 raise
 
         else:
             response_status = str(response.status_code) + ' ' + response.reason
-            message = u'SIP search failed. Reason: response status != 200. status={0}, content={1}'.format(
+            message = 'SIP search failed. Reason: response status != 200. status={0}, content={1}'.format(
                 response_status,
                 response.text)
             log.error(message)
             raise SearchException(message,
-                sip_info=u'HTTP error "{status}" while searching upstream database'.format(status=response_status))
+                sip_info='HTTP error "{status}" while searching upstream database'.format(status=response_status))
 
 
     def getresults(self, resultid, options):
@@ -207,23 +207,23 @@ def getresults(self, resultid, options):
                         raise SearchException(message)
 
                     duration = timeit.default_timer() - starttime
-                    log.info(u'SIP getresults succeeded. duration={0}s'.format(round(duration, 1)))
+                    log.info('SIP getresults succeeded. duration={0}s'.format(round(duration, 1)))
                     return results
 
             except SearchException:
                 raise
 
             except Exception as ex:
-                message = u'SIP getresults failed. Unknown exception. Reason: {0} {1}'.format(
+                message = 'SIP getresults failed. Unknown exception. Reason: {0} {1}'.format(
                     ex.__class__, ex.message)
-                logmessage = u'{}. response={}'.format(message, response.text)
+                logmessage = '{}. response={}'.format(message, response.text)
                 log.error(logmessage)
                 raise SearchException(message)
 
         else:
-            message = u'SIP getresults failed. status_code={0}'.format(
+            message = 'SIP getresults failed. status_code={0}'.format(
                 str(response.status_code) + ' ' + response.reason)
-            logmessage = u'{}. response={}'.format(message, response.text)
+            logmessage = '{}. response={}'.format(message, response.text)
             log.error(logmessage)
             raise SearchException(message)
 
@@ -243,8 +243,8 @@ def _login_parse_xml(self, xml):
                               'this happens regularly on Wednesday evenings at 17:00 hours UTC (19:00 hours CEST)<br/>' \
                               'and usually does not take longer than one hour.'
 
-        if error.sip_info == u'i':
-            error.sip_info = u'Login failed'
+        if error.sip_info == 'i':
+            error.sip_info = 'Login failed'
         raise error
 
     def _search_parse_xml(self, xml):
@@ -329,15 +329,15 @@ def read(self):
             # TODO: Reference from IFI CLAIMS, fill up/unify.
             #'time': self.input['time'],
             #'status': self.input['status'],
-            #'params': SmartBunch.bunchify(self.input['content']['responseHeader']['params']),
-            #'pager': SmartBunch.bunchify(self.input['content']['responseHeader'].get('pager', {})),
+            #'params': SmartMunch.munchify(self.input['content']['responseHeader']['params']),
+            #'pager': SmartMunch.munchify(self.input['content']['responseHeader'].get('pager', {})),
         })
 
         self.meta.navigator.count_total = int(self.meta.upstream.MemCount)
         self.meta.navigator.count_page  = len(self.input['results'])
         self.meta.navigator.offset      = int(self.meta.upstream.Offset)
         self.meta.navigator.limit       = int(self.meta.upstream.Limit)
-        self.meta.navigator.postprocess = SmartBunch()
+        self.meta.navigator.postprocess = SmartMunch()
 
         # Read content
         """
diff --git a/patzilla/access/sip/clientpool.py b/patzilla/access/sip/clientpool.py
index f28a8c3c..1c8e679d 100644
--- a/patzilla/access/sip/clientpool.py
+++ b/patzilla/access/sip/clientpool.py
@@ -4,8 +4,9 @@
 import os
 
 from pyramid.httpexceptions import HTTPUnauthorized
-from zope.interface.declarations import implements
+from zope.interface import implementer
 from zope.interface.interface import Interface
+from zope.interface import implementer
 
 from patzilla.access.generic.credentials import AbstractCredentialsGetter, DatasourceCredentialsManager
 from patzilla.access.sip.client import SipClient
@@ -45,6 +46,8 @@ def from_settings(datasource_settings):
 
     @staticmethod
     def from_environment():
+        if not os.environ["SIP_API_USERNAME"] or not os.environ["SIP_API_PASSWORD"]:
+            raise KeyError("SIP_API_USERNAME or SIP_API_PASSWORD is empty")
         return {
             "api_username": os.environ["SIP_API_USERNAME"],
             "api_password": os.environ["SIP_API_PASSWORD"],
@@ -80,13 +83,12 @@ class ISipClientPool(Interface):
     pass
 
 
+@implementer(ISipClientPool)
 class SipClientPool(object):
     """
     SIP client pool as Pyramid utility implementation.
     """
 
-    implements(ISipClientPool)
-
     def __init__(self, api_uri):
         logger.info("Creating upstream client pool for SIP")
         self.api_uri = api_uri
@@ -103,3 +105,4 @@ def get(self, identifier, credentials=None, debug=False):
                 uri=self.api_uri, username=credentials['api_username'], password=credentials['api_password'])
 
         return self.clients.get(identifier)
+
diff --git a/patzilla/access/sip/concordance.py b/patzilla/access/sip/concordance.py
index 210371ab..ac9f44f8 100644
--- a/patzilla/access/sip/concordance.py
+++ b/patzilla/access/sip/concordance.py
@@ -202,7 +202,7 @@ def decode_row(row):
 
         try:
             stream = DictReader(csvfile)
-            print stream.fieldnames
+            print(stream.fieldnames)
         except Exception as ex:
             log.error('SIP CPC class map: Reading CSV file {} failed: {}'.format(filename, ex.message))
             return
@@ -225,7 +225,7 @@ def decode_row(row):
             return
 
         ws = wb.active
-        print 'XLSX row 1:', [cell.value for cell in ws.rows[0]]
+        print('XLSX row 1:', [cell.value for cell in ws.rows[0]])
         stream = ws.rows[1:20]
 
     #sys.exit(1)
diff --git a/patzilla/access/sip/expression.py b/patzilla/access/sip/expression.py
index b5254f38..cc0e1583 100644
--- a/patzilla/access/sip/expression.py
+++ b/patzilla/access/sip/expression.py
@@ -49,16 +49,16 @@ class SipExpression(object):
         }
 
     sip_xml_expression_templates = {
-        'patentnumber': u'<patentnumber>{value}</patentnumber>',
-        'fulltext':     u'<text searchintitle="{title}" searchinabstract="{abstract}" searchinclaim="{claim}" searchindescription="{description}" fullfamily="false">{value}</text>',
+        'patentnumber': '<patentnumber>{value}</patentnumber>',
+        'fulltext':     '<text searchintitle="{title}" searchinabstract="{abstract}" searchinclaim="{claim}" searchindescription="{description}" fullfamily="false">{value}</text>',
         #'applicant':    u'<applicant type="epo,inpadoc,original">{value}</applicant>',
         #'inventor':     u'<inventor type="epo,inpadoc,original">{value}</inventor>',
-        'applicant':    u'<applicant type="epo,original">{value}</applicant>',
-        'inventor':     u'<inventor type="epo,original">{value}</inventor>',
+        'applicant':    '<applicant type="epo,original">{value}</applicant>',
+        'inventor':     '<inventor type="epo,original">{value}</inventor>',
         'pubdate':      {
-            'both':      u'<date type="publication" startdate="{startdate}" enddate="{enddate}" />',
-            'startdate': u'<date type="publication" startdate="{startdate}" />',
-            'enddate':   u'<date type="publication" enddate="{enddate}" />',
+            'both':      '<date type="publication" startdate="{startdate}" enddate="{enddate}" />',
+            'startdate': '<date type="publication" startdate="{startdate}" />',
+            'enddate':   '<date type="publication" enddate="{enddate}" />',
             }
     }
 
@@ -83,11 +83,11 @@ def pair_to_sip_xml(cls, key, value, modifiers):
         # {u'fulltext': {u'claim': True, u'abstract': True, u'description': True, u'title': True}
         # ->
         # {u'fulltext': {u'claim': 'true', u'abstract': 'true', u'description': 'true', u'title': 'true'}
-        for modifier_field, modifier_values in modifiers.iteritems():
-            if type(modifiers[modifier_field]) is types.DictionaryType:
-                for modifier_name, modifier_value in modifiers[modifier_field].iteritems():
+        for modifier_field, modifier_values in modifiers.items():
+            if type(modifiers[modifier_field]) is dict:
+                for modifier_name, modifier_value in modifiers[modifier_field].items():
                     modifiers[modifier_field][modifier_name] = str(modifier_value).lower()
-            elif type(modifiers[modifier_field]) is types.BooleanType:
+            elif type(modifiers[modifier_field]) is bool:
                 modifiers[modifier_field] = str(modifiers[modifier_field]).lower()
 
         xml_part = None
@@ -99,7 +99,7 @@ def pair_to_sip_xml(cls, key, value, modifiers):
 
                 if len(value) == 4 and value.isdigit():
                     # e.g. 1978
-                    value = u'within {year}-01-01,{year}-12-31'.format(year=value)
+                    value = 'within {year}-01-01,{year}-12-31'.format(year=value)
 
                 # e.g. 1990-2014, 1990 - 2014
                 value = year_range_to_within(value)
@@ -198,13 +198,13 @@ def pair_to_sip_xml(cls, key, value, modifiers):
                 #print pretty_print(xml_part)
 
             except FulltextDecodingError as ex:
-                return {'error': True, 'message': unicode(ex)}
+                return {'error': True, 'message': str(ex)}
 
             except pyparsing.ParseException as ex:
-                return {'error': True, 'message': u'<pre>' + ex.explanation + '</pre>'}
+                return {'error': True, 'message': '<pre>' + ex.explanation + '</pre>'}
 
             except SyntaxError as ex:
-                return {'error': True, 'message': u'<pre>' + unicode(ex) + '</pre>'}
+                return {'error': True, 'message': '<pre>' + str(ex) + '</pre>'}
 
         elif key in cls.sip_xml_expression_templates:
             template = cls.sip_xml_expression_templates[key]
@@ -232,7 +232,7 @@ def pair_to_sip_xml(cls, key, value, modifiers):
     def compute_modifiers(cls, modifiers):
 
         # prefer defaults (all True), but mixin modifiers from query
-        for modifier_field, modifier_values in cls.modifier_defaults.iteritems():
+        for modifier_field, modifier_values in cls.modifier_defaults.items():
             if modifier_field in cls.modifier_defaults:
                 backup = deepcopy(modifiers.get(modifier_field, {}))
                 modifiers[modifier_field] = cls.modifier_defaults[modifier_field]
@@ -313,8 +313,8 @@ def to_etree(self, expression):
             result = self.parser._parser(expression, parseAll=True)
 
         except pyparsing.ParseException as ex:
-            ex.explanation = u'%s\n%s\n%s' % (expression, u' ' * ex.loc + u'^\n', ex)
-            logger.error(u'\n%s', ex.explanation)
+            ex.explanation = '%s\n%s\n%s' % (expression, ' ' * ex.loc + '^\n', ex)
+            logger.error('\n%s', ex.explanation)
             raise
 
         #print 'result:', result, type(result), dir(result)
@@ -487,16 +487,16 @@ def parse(self):
         def eexists(element, name):
             return element.find(name) is not None
         child_constraints =\
-            all(map(lambda x: eexists(root, x), ['index', 'binop'])) and \
-            any(map(lambda x: eexists(root, x), ['value', 'quotes']))
+            all([eexists(root, x) for x in ['index', 'binop']]) and \
+            any([eexists(root, x) for x in ['value', 'quotes']])
         if root.tag == 'parenthesis' and child_constraints:
             root.tag = 'term'
 
         # also rewrite all other parenthesis looking like terms
         for parens in root.iter('parenthesis'):
             child_constraints =\
-                all(map(lambda x: eexists(parens, x), ['index', 'binop'])) and\
-                any(map(lambda x: eexists(parens, x), ['value', 'quotes', 'or', 'and', 'not']))
+                all([eexists(parens, x) for x in ['index', 'binop']]) and\
+                any([eexists(parens, x) for x in ['value', 'quotes', 'or', 'and', 'not']])
             if child_constraints:
                 parens.tag = 'term'
 
@@ -522,7 +522,7 @@ def eexists(element, name):
 
             elif boolean_content:
                 value = self.convert_boolean_nodes(term)
-                value = value.replace(u'and not', u'not')
+                value = value.replace('and not', 'not')
 
 
             # 2. expand triple
@@ -600,7 +600,7 @@ def convert_elements(self, root, element, tags):
             # skip elements without a valid representation on this level, e.g. "(ab=fahrzeug or ab=pkw)"
             if not value:
                 return root
-            value = value.replace(u'and not', u'not')
+            value = value.replace('and not', 'not')
 
         elif tag in ['near', 'span']:
             value = self.convert_proximity_nodes(element_nested)
@@ -628,13 +628,13 @@ def _get_index_binop(self, element):
         if index_node is not None:
             index = index_node.text
         else:
-            index = u'bi'
+            index = 'bi'
 
         # 2. binop
         if binop_node is not None:
             binop = binop_node.text
         else:
-            binop = u'='
+            binop = '='
 
         return index, binop
 
@@ -667,14 +667,14 @@ def convert_proximity_nodes(self, container):
 
         # fall back to using already translated "text" nodes
         if value:
-            expression = map(lambda x: x.text, value)
-            map(lambda x: self.keyword_add(x), expression)
+            expression = [x.text for x in value]
+            list(map(lambda x: self.keyword_add(x), expression))
         elif text:
-            expression = map(lambda x: '({0})'.format(x.text), text)
+            expression = ['({0})'.format(x.text) for x in text]
 
-        expression = u' '.join(expression)
+        expression = ' '.join(expression)
         distance = distance[0].text
-        value = u'{operator}({expression}, {distance})'.format(operator=container.tag, expression=expression, distance=distance)
+        value = '{operator}({expression}, {distance})'.format(operator=container.tag, expression=expression, distance=distance)
         return value
 
     def convert_boolean_nodes(self, node):
@@ -693,7 +693,7 @@ def convert_boolean_nodes(self, node):
             elif element.tag == 'parenthesis':
                 result = self.convert_boolean_nodes(element)
                 if result:
-                    result = u'(' + result + u')'
+                    result = '(' + result + ')'
                 child_values.append(result)
 
             elif element.tag in ['near', 'span']:
@@ -706,9 +706,9 @@ def convert_boolean_nodes(self, node):
                 pass
 
         if len(child_values) == 1 and node.tag == 'not':
-            child_values = [u'not ' + child_values[0]]
+            child_values = ['not ' + child_values[0]]
 
-        return u' {0} '.format(node.tag).join(child_values)
+        return ' {0} '.format(node.tag).join(child_values)
 
     def decode_quoted_value(self, element):
         """
@@ -731,15 +731,15 @@ def decode_quoted_value(self, element):
             value = element.text
 
         elif element.tag == 'quotes':
-            values = map(lambda x: x.text, element.iter('value'))
-            value = u'"{0}"'.format(u' '.join(values))
+            values = [x.text for x in element.iter('value')]
+            value = '"{0}"'.format(' '.join(values))
 
         return value
 
     def expand_fulltext(self, value, origin=None, modifiers=None):
         triple = value
 
-        origin = origin or u'{0}{1}{2}'.format(*triple)
+        origin = origin or '{0}{1}{2}'.format(*triple)
 
         ft_field, ft_op, ft_value = triple
 
@@ -753,15 +753,15 @@ def expand_fulltext(self, value, origin=None, modifiers=None):
             try:
                 ft_modifier = SipExpression.fulltext_field_modifier_map[ft_field]
             except KeyError:
-                message = u'SIP expression "{0}" contains unknown index "{1}".'.format(origin, ft_field)
+                message = 'SIP expression "{0}" contains unknown index "{1}".'.format(origin, ft_field)
                 logger.warn(message)
                 raise FulltextDecodingError(message)
 
             ft_modifiers = SipExpression.fulltext_modifiers_off.copy()
 
-            if type(ft_modifier) in types.StringTypes:
+            if type(ft_modifier) in (str,):
                 ft_modifiers.update({ft_modifier: 'true'})
-            elif type(ft_modifier) is types.ListType:
+            elif type(ft_modifier) is list:
                 for ft_mod_item in ft_modifier:
                     ft_modifiers.update({ft_mod_item: 'true'})
 
@@ -776,10 +776,10 @@ def strip_accents(s):
     #return ''.join((c for c in unicodedata.normalize('NFD', unicode(s)) if unicodedata.category(c) != 'Mn'))
     result = []
     for char in s:
-        if char.lower() in u'äöüß':
+        if char.lower() in 'äöüß':
             result.append(char)
         else:
-            char_decomposed = unicodedata.normalize('NFD', unicode(char))
+            char_decomposed = unicodedata.normalize('NFD', str(char))
             for cd in char_decomposed:
                 if unicodedata.category(cd) != 'Mn':
                     result.append(cd)
diff --git a/patzilla/access/sip/pyramid_service.py b/patzilla/access/sip/pyramid_service.py
index 51fb44b5..225a3928 100644
--- a/patzilla/access/sip/pyramid_service.py
+++ b/patzilla/access/sip/pyramid_service.py
@@ -12,7 +12,7 @@
 from patzilla.access.sip.client import sip_published_data_search, sip_published_data_crawl, SearchException
 from patzilla.access.sip.client import LoginException
 from patzilla.util.cql.util import should_be_quoted
-from patzilla.util.data.container import SmartBunch
+from patzilla.util.data.container import SmartMunch
 from patzilla.util.python import _exception_traceback
 
 log = logging.getLogger(__name__)
@@ -58,7 +58,7 @@ def sip_published_data_search_handler(request):
     # - sorting
     # - whether to remove family members
     # - whether to return all family members
-    options = SmartBunch()
+    options = SmartMunch()
     options.update({
         'limit':  limit,
         'offset': offset_remote,
@@ -94,8 +94,8 @@ def sip_published_data_search_handler(request):
         return ex.data
 
     except OperationFailure as ex:
-        message = unicode(ex)
-        message = re.sub(u'namespace: .*', u'', message)
+        message = str(ex)
+        message = re.sub('namespace: .*', '', message)
         request.errors.add('sip-search', 'internals', message)
         log.error(request.errors)
 
@@ -126,7 +126,7 @@ def sip_published_data_crawl_handler(request):
         if hasattr(ex, 'user_info'):
             message = ex.user_info
         else:
-            message = unicode(ex)
+            message = str(ex)
         request.errors.add('sip-crawl', 'crawl', message)
         log.error(request.errors)
-        log.error(u'query="{0}", exception:\n{1}'.format(query, _exception_traceback()))
+        log.error('query="{0}", exception:\n{1}'.format(query, _exception_traceback()))
diff --git a/patzilla/access/uspto/pdf.py b/patzilla/access/uspto/pdf.py
index a31b8cbf..ef9b7ccc 100644
--- a/patzilla/access/uspto/pdf.py
+++ b/patzilla/access/uspto/pdf.py
@@ -119,7 +119,7 @@ def get_reference_type(document):
     Analyze document number to tell application vs. patent (publication, grant) numbers apart.
     The basic heuristic is to assume e.g. US2007231208A1 (4+6=10 chars) to be an application.
     """
-    if document is None or not (hasattr(document, "number") and isinstance(document.number, (int, str, unicode))):
+    if document is None or not (hasattr(document, "number") and isinstance(document.number, (int, str, bytes))):
         raise ValueError("Unknown document reference type: {}".format(document))
     number_length = len(str(document.number))
     reference_type = None
diff --git a/patzilla/boot/config.py b/patzilla/boot/config.py
index ae75b9f9..c3d02580 100644
--- a/patzilla/boot/config.py
+++ b/patzilla/boot/config.py
@@ -90,7 +90,7 @@ def tmpfile(self, payload, suffix=None):
         """
         Create a temporary file with given content.
         """
-        tmp = tempfile.NamedTemporaryFile(suffix=suffix)
+        tmp = tempfile.NamedTemporaryFile(mode='w+', suffix=suffix)
         self._tmpfiles.append(tmp)
         tmp.write(payload)
         tmp.flush()
diff --git a/patzilla/navigator/export.py b/patzilla/navigator/export.py
index 8328001e..6bb6251a 100644
--- a/patzilla/navigator/export.py
+++ b/patzilla/navigator/export.py
@@ -15,7 +15,7 @@
 from io import BytesIO
 from textwrap import dedent
 from lxml import etree as ET
-from bunch import bunchify, Bunch
+from munch import munchify, Munch
 from json.encoder import JSONEncoder
 from zipfile import ZipFile, ZIP_DEFLATED
 from collections import OrderedDict
@@ -34,7 +34,7 @@
 
 class Dossier(object):
 
-    summary_template = dedent(u"""
+    summary_template = dedent("""
         Summary
 
         The research about »{project_name}«
@@ -53,7 +53,7 @@ class Dossier(object):
         """).strip()
 
     def __init__(self, data):
-        self.data = bunchify(data)
+        self.data = munchify(data)
         self.prepare_dataframes()
         self.make_metadata()
 
@@ -61,7 +61,7 @@ def make_metadata(self):
 
         self.metadata = ReportMetadata()
 
-        self.metadata.set('producer', u'IP Navigator')
+        self.metadata.set('producer', 'IP Navigator')
 
         # Project metadata
         self.metadata.set('project_name',     self.data.project.name)
@@ -120,7 +120,7 @@ def prepare_dataframes(self):
 
 
         # Queries
-        queries = map(self.query_criteria_smoother, self.data.get('queries', []))
+        queries = list(map(self.query_criteria_smoother, self.data.get('queries', [])))
         self.df_queries = pandas.DataFrame(queries, columns=['criteria', 'query_expression', 'result_count', 'datasource', 'created'])
         self.df_queries.rename(columns={'query_expression': 'expression', 'result_count': 'hits', 'created': 'timestamp'}, inplace=True)
 
@@ -155,10 +155,10 @@ def get_summary(self):
 
     def get_metadata(self):
         return self.format_with_metadata(
-            u'Author:   {author_name} <{author_email}>\n'
-            u'Created:  {project_created}\n'
-            u'Updated:  {project_modified}\n'
-            u'Producer: {producer}')
+            'Author:   {author_name} <{author_email}>\n'
+            'Created:  {project_created}\n'
+            'Updated:  {project_modified}\n'
+            'Producer: {producer}')
 
     @staticmethod
     def to_csv(dataframe):
@@ -189,7 +189,7 @@ def to_zip(self, request=None, options=None):
         # TODO: Text representations for biblio, register, family
         # TODO: PDF Extracts
 
-        options = options or bunchify({'report': {}, 'media': {}})
+        options = options or munchify({'report': {}, 'media': {}})
 
 
         # Remove entries with empty/undefined document numbers
@@ -203,7 +203,7 @@ def to_zip(self, request=None, options=None):
         with ZipFile(buffer, 'w', ZIP_DEFLATED) as zipfile:
 
             # FIXME: Add TERMS (liability waiver) and more...
-            zipfile.writestr('@readme.txt', u'Zip archive created by IP Navigator.')
+            zipfile.writestr('@readme.txt', 'Zip archive created by IP Navigator.')
 
             # Add text summary
             zipfile.writestr('@metadata.txt', self.get_metadata().encode('utf-8'))
@@ -224,8 +224,8 @@ def to_zip(self, request=None, options=None):
                 try:
                     zipfile.writestr('report/@dossier.pdf', DossierXlsx(self.data).to_pdf(payload=workbook_payload))
                 except Exception as ex:
-                    log.error(u'Rendering dossier to PDF failed. ' \
-                              u'Exception: {ex}\n{trace}'.format(ex=ex, trace=exception_traceback()))
+                    log.error('Rendering dossier to PDF failed. ' \
+                              'Exception: {ex}\n{trace}'.format(ex=ex, trace=exception_traceback()))
 
             # Add CSV
             if options.report.csv:
@@ -263,7 +263,7 @@ def to_zip(self, request=None, options=None):
                 if not document or not document.strip():
                     continue
 
-                log.info(u'Data acquisition for document {document}'.format(document=document))
+                log.info('Data acquisition for document {document}'.format(document=document))
 
                 status.setdefault(document, OrderedDict())
                 patent = decode_patent_number(document)
@@ -272,7 +272,7 @@ def to_zip(self, request=None, options=None):
                 if options.media.biblio:
                     try:
                         biblio_payload = get_ops_biblio_data('publication', document, xml=True)
-                        zipfile.writestr(u'media/xml/{document}.biblio.xml'.format(document=document), biblio_payload)
+                        zipfile.writestr('media/xml/{document}.biblio.xml'.format(document=document), biblio_payload)
                         status[document]['biblio'] = True
 
                     except Exception as ex:
@@ -290,14 +290,14 @@ def to_zip(self, request=None, options=None):
                             # Write XML
                             document_number = encode_epodoc_number(patent)
                             description_payload = ops_description(document_number, xml=True)
-                            zipfile.writestr(u'media/xml/{document}.description.xml'.format(document=document), description_payload)
+                            zipfile.writestr('media/xml/{document}.description.xml'.format(document=document), description_payload)
                             status[document]['description'] = True
 
                             # Write TEXT
                             with ignored():
                                 text_payload = self.get_fulltext(description_payload, 'description')
                                 if text_payload:
-                                    zipfile.writestr(u'media/txt/{document}.description.txt'.format(document=document), text_payload.encode('utf-8'))
+                                    zipfile.writestr('media/txt/{document}.description.txt'.format(document=document), text_payload.encode('utf-8'))
 
                         except Exception as ex:
                             self.handle_exception(ex, 'description', document)
@@ -313,14 +313,14 @@ def to_zip(self, request=None, options=None):
                             # Write XML
                             document_number = encode_epodoc_number(patent)
                             claims_payload = ops_claims(document_number, xml=True)
-                            zipfile.writestr(u'media/xml/{document}.claims.xml'.format(document=document), claims_payload)
+                            zipfile.writestr('media/xml/{document}.claims.xml'.format(document=document), claims_payload)
                             status[document]['claims'] = True
 
                             # Write TEXT
                             with ignored():
                                 text_payload = self.get_fulltext(claims_payload.replace('<claim-text>', '<p>').replace('</claim-text>', '</p>'), 'claims')
                                 if text_payload:
-                                    zipfile.writestr(u'media/txt/{document}.claims.txt'.format(document=document), text_payload.encode('utf-8'))
+                                    zipfile.writestr('media/txt/{document}.claims.txt'.format(document=document), text_payload.encode('utf-8'))
 
                         except Exception as ex:
                             self.handle_exception(ex, 'claims', document)
@@ -332,7 +332,7 @@ def to_zip(self, request=None, options=None):
 
                     try:
                         register_payload = ops_register('publication', document, xml=True)
-                        zipfile.writestr(u'media/xml/{document}.register.xml'.format(document=document), register_payload)
+                        zipfile.writestr('media/xml/{document}.register.xml'.format(document=document), register_payload)
                         status[document]['register'] = True
 
                     except Exception as ex:
@@ -346,7 +346,7 @@ def to_zip(self, request=None, options=None):
                     try:
                         document_number = encode_epodoc_number(patent, options={'nokind': True})
                         family_payload = ops_family_inpadoc('publication', document_number, 'biblio', xml=True)
-                        zipfile.writestr(u'media/xml/{document}.family.xml'.format(document=document), family_payload)
+                        zipfile.writestr('media/xml/{document}.family.xml'.format(document=document), family_payload)
                         status[document]['family'] = True
 
                     except Exception as ex:
@@ -368,20 +368,20 @@ def to_zip(self, request=None, options=None):
 
             delivered_items = []
             missing_items = []
-            for document, kinds in status.iteritems():
+            for document, kinds in status.items():
                 delivered = []
                 missing = []
-                for kind, ok in kinds.iteritems():
+                for kind, ok in kinds.items():
                     if ok:
                         delivered.append(kind)
                     else:
                         missing.append(kind)
 
                 if delivered:
-                    item = u'{document:20}{delivered}'.format(document=document, delivered=u', '.join(delivered))
+                    item = '{document:20}{delivered}'.format(document=document, delivered=', '.join(delivered))
                     delivered_items.append(item)
                 if missing:
-                    item = u'{document:20}{missing}'.format(document=document, missing=u', '.join(missing))
+                    item = '{document:20}{missing}'.format(document=document, missing=', '.join(missing))
                     missing_items.append(item)
 
             if delivered_items or missing_items:
@@ -409,13 +409,13 @@ def to_zip(self, request=None, options=None):
 
     def handle_exception(self, ex, service_name, document):
         if isinstance(ex, (_JSONError, HTTPError)) and hasattr(ex, 'status_int') and ex.status_int == 404:
-            log.warning(u'XML({service_name}, {document}) not found'.format(service_name=service_name, document=document))
+            log.warning('XML({service_name}, {document}) not found'.format(service_name=service_name, document=document))
 
             # Signal exception has been handled (ignored)
             return True
         else:
-            log.warning(u'XML({service_name}, {document}) failed. ' \
-                        u'Exception:\n{trace}'.format(service_name=service_name, document=document, trace=exception_traceback()))
+            log.warning('XML({service_name}, {document}) failed. ' \
+                        'Exception:\n{trace}'.format(service_name=service_name, document=document, trace=exception_traceback()))
 
         # Signal exception should be re-raised, maybe
         return False
@@ -464,7 +464,7 @@ def default(self, o):
                 return JSONEncoder.default(self, o)
 
         """
-        if isinstance(o, (numpy.bool_,)):
+        if isinstance(o, numpy.bool_):
             return bool(o)
 
         raise TypeError(repr(o) + " is not JSON serializable")
@@ -512,9 +512,9 @@ def create(self):
 
     def set_header_footer(self, worksheet):
         # http://xlsxwriter.readthedocs.io/example_headers_footers.html
-        header = u'&LIP Navigator&RSearch report'
+        header = '&LIP Navigator&RSearch report'
         worksheet.set_header(header)
-        footer = u'&L&L&D &T&C&A&RPage &P of &N'
+        footer = '&L&L&D &T&C&A&RPage &P of &N'
         worksheet.set_footer(footer)
 
     def write_cover_sheet(self):
@@ -529,7 +529,7 @@ def write_cover_sheet(self):
         cover_sheet = self.workbook.add_worksheet('cover')
         self.set_header_footer(cover_sheet)
 
-        title = u'Dossier »{name}«'.format(name=self.data.project.name)
+        title = 'Dossier »{name}«'.format(name=self.data.project.name)
         title_format = self.workbook.add_format({'align': 'center', 'valign': 'vcenter', 'font_size': 17, 'bold': True})
         cover_sheet.merge_range('A1:I2', title, title_format)
 
@@ -545,7 +545,7 @@ def write_cover_sheet(self):
 
 
         footnote_format = self.workbook.add_format({'font_size': 9})
-        footnote = dedent(u"""
+        footnote = dedent("""
         Please have a look at the other worksheets in
         this workbook for more detailed information about
         all queries, comments and document numbers
@@ -554,7 +554,7 @@ def write_cover_sheet(self):
 
         summary = self.generate_with_metadata(self.summary_template, emphasis=blue)
 
-        args = list(summary) + ['\n'] + [footnote_format, u'\n\n' + footnote]
+        args = list(summary) + ['\n'] + [footnote_format, '\n\n' + footnote]
         args.append(cell_format)
         cover_sheet.write_rich_string('B10', *args)
 
@@ -571,7 +571,7 @@ def write_numberlist_sheets(self):
         sheets['rated']     = self.data.get('collections', {}).get('rated')
         sheets['dismissed'] = self.data.get('collections', {}).get('dismissed')
         sheets['seen']      = self.data.get('collections', {}).get('seen')
-        for sheet_name, entries in sheets.iteritems():
+        for sheet_name, entries in sheets.items():
 
             #print 'entries:'; pprint(entries)
 
@@ -581,10 +581,10 @@ def write_numberlist_sheets(self):
                 first = {}
 
             # Create pandas DataFrame
-            if type(first) in types.StringTypes:
+            if type(first) in (str,):
                 df = pandas.DataFrame(entries, columns=['PN'])
 
-            elif isinstance(first, (types.DictionaryType, Bunch)):
+            elif isinstance(first, (dict, Munch)):
                 df = pandas.DataFrame(entries, columns=['number', 'score', 'timestamp', 'url'])
                 df.rename(columns={'number': 'document', 'url': 'display'}, inplace=True)
 
@@ -720,7 +720,7 @@ def to_pdf(self, payload=None):
 
         if process.status_code == 0:
             #pdf_name = os.path.join(pdf_path, os.path.basename(xlsx_file.name).replace('.xlsx', '.pdf'))
-            payload = file(pdf_path, 'r').read()
+            payload = open(pdf_path, 'rb').read()
             #shutil.rmtree(pdf_path)
             os.unlink(pdf_path)
             return payload
@@ -750,7 +750,7 @@ def set(self, key, value):
 
     # https://stackoverflow.com/questions/17215400/python-format-string-unused-named-arguments/17215533#17215533
     def __missing__(self, key):
-        return u'n/a'
+        return 'n/a'
 
 
 # Machinery for monkeypatching XlsxWriter's Worksheet's ``write_url`` method
@@ -763,7 +763,7 @@ def write_url_deduce_title(self, row, col, url, cell_format=None, string=None, t
     if string is None:
         string = os.path.basename(url)
     if tip is None:
-        tip = u'Open "{name}" in Patent Navigator'.format(name=string)
+        tip = 'Open "{name}" in Patent Navigator'.format(name=string)
     return self.write_url_dist(row, col, url, cell_format=cell_format, string=string, tip=tip)
 
 def workbook_add_sheet_hook(self, name=None):
@@ -810,8 +810,8 @@ def _vgenerate(self, format_string, args, kwargs, used_args, recursion_depth):
                 obj = self.convert_field(obj, conversion)
 
                 # expand the format spec, if needed
-                format_spec = self._vformat(format_spec, args, kwargs,
-                    used_args, recursion_depth-1)
+                #format_spec = self._vformat(format_spec, args, kwargs,
+                    #used_args, recursion_depth-1)
 
                 # format the object and append to the result
                 if 'emphasis' in kwargs:
diff --git a/patzilla/navigator/services/__init__.py b/patzilla/navigator/services/__init__.py
index be31f855..8355b43e 100644
--- a/patzilla/navigator/services/__init__.py
+++ b/patzilla/navigator/services/__init__.py
@@ -35,12 +35,11 @@ def handle_generic_exception(request, ex, backend_name, query):
 
     module_name = ex.__class__.__module__
     class_name = ex.__class__.__name__
-    reason = u'{}.{}: {}'.format(module_name, class_name, ex.message)
+    reason = '{}.{}: {}'.format(module_name, class_name, str(ex))
 
-    logger.critical(u'{backend_name} error: query="{query}", reason={reason}\nresponse:\n{http_response}\nexception:\n{exception}'.format(
-        exception=_exception_traceback(), **locals()))
+    logger.exception('{backend_name} error: query="{query}", reason={reason}\nresponse:\n{http_response}'.format(**locals()))
 
-    message = u'An exception occurred while processing your query.<br/>\nReason: {}<br/><br/>\n'.format(reason)
+    message = 'An exception occurred while processing your query.<br/>\nReason: {}<br/><br/>\n'.format(reason)
     if module_name == 'pymongo.errors':
         message += 'Error connecting to cache database. Please report this problem to us.'
 
diff --git a/patzilla/navigator/services/admin.py b/patzilla/navigator/services/admin.py
index 28aef93b..62db0094 100644
--- a/patzilla/navigator/services/admin.py
+++ b/patzilla/navigator/services/admin.py
@@ -30,7 +30,7 @@ def admin_users_emails_handler(request):
             continue
         user_emails.append(user.username.lower())
 
-    payload = u'\n'.join(user_emails)
+    payload = '\n'.join(user_emails)
 
     return Response(payload, content_type='text/plain', charset='utf-8')
 
diff --git a/patzilla/navigator/services/analytics.py b/patzilla/navigator/services/analytics.py
index 3bce27ce..c73923da 100644
--- a/patzilla/navigator/services/analytics.py
+++ b/patzilla/navigator/services/analytics.py
@@ -3,7 +3,7 @@
 import logging
 import datetime
 import operator
-import HTMLParser
+import html.parser
 from arrow.arrow import Arrow
 from cornice.service import Service
 from dateutil.relativedelta import relativedelta
@@ -63,7 +63,7 @@ def _decode_expression_from_query(request):
     # decode query parameters into datasource and criteria
     decoded = {}
     params = dict(request.params)
-    if params.has_key('datasource'):
+    if 'datasource' in params:
         decoded['datasource'] = params['datasource'].lower()
         del params['datasource']
     decoded.update({'criteria': params})
@@ -96,7 +96,7 @@ def __init__(self, datasource, criteria, kind):
 
 
         if self.kind == self.OLDEST:
-            self.date_from = Arrow.fromdatetime(datetime.datetime(1800, 01, 01))
+            self.date_from = Arrow.fromdatetime(datetime.datetime(1800, 0o1, 0o1))
             self.date_to   = Arrow.fromdatetime(datetime.datetime(1899, 12, 31))
             self.factor    = +1
 
@@ -106,7 +106,7 @@ def __init__(self, datasource, criteria, kind):
             self.machine.add_transition('step',  'right', 'whole', unless='is_ready', after=['range_shrink'])
 
         elif self.kind == self.NEWEST:
-            self.date_from = Arrow.fromdatetime(datetime.datetime(2000, 01, 01))
+            self.date_from = Arrow.fromdatetime(datetime.datetime(2000, 0o1, 0o1))
             self.date_to   = Arrow.utcnow()
             self.date_to   += relativedelta(months=12-self.date_to.month, days=31-self.date_to.day)
             self.factor    = -1
@@ -124,7 +124,7 @@ def __init__(self, datasource, criteria, kind):
 
     def runquery(self):
         criteria = self.criteria.copy()
-        criteria['pubdate'] = u'within {date_from},{date_to}'.format(
+        criteria['pubdate'] = 'within {date_from},{date_to}'.format(
                          date_from=self.date_from.format('YYYY-MM-DD'), date_to=self.date_to.format('YYYY-MM-DD'))
 
         query = make_expression_filter({
@@ -199,10 +199,10 @@ def work(self):
         debug = False
         while True:
             if debug:
-                print '-' * 42
-                print 'state:', self.state
-                print 'delta:', self.delta
-                print 'querycount:', self.querycount
+                print('-' * 42)
+                print('state:', self.state)
+                print('delta:', self.delta)
+                print('querycount:', self.querycount)
             if self.state == 'finished' or self.querycount > 15:
                 break
             self.step()
@@ -294,7 +294,7 @@ def analytics_applicants_distinct_handler(request):
     #print 'results:', results
 
     applicants = {}
-    htmlparser = HTMLParser.HTMLParser()
+    htmlparser = html.parser.HTMLParser()
     for item in results['details']:
         applicant = item.get('applicant')
         if applicant:
diff --git a/patzilla/navigator/services/depatech.py b/patzilla/navigator/services/depatech.py
index f852a81d..bae75f29 100644
--- a/patzilla/navigator/services/depatech.py
+++ b/patzilla/navigator/services/depatech.py
@@ -14,7 +14,7 @@
 from patzilla.util.expression.keywords import keywords_to_response
 from patzilla.navigator.services.util import request_to_options
 from patzilla.access.generic.exceptions import NoResultsException, SearchException
-from patzilla.util.data.container import SmartBunch
+from patzilla.util.data.container import SmartMunch
 from patzilla.util.python import _exception_traceback
 
 log = logging.getLogger(__name__)
@@ -37,7 +37,7 @@
 @status_upstream_depatech.get()
 def status_upstream_depatech_handler(request):
     client = get_depatech_client()
-    query = SmartBunch({
+    query = SmartMunch({
         'expression': '(PC:DE AND DE:212016000074 AND KI:U1) OR AN:DE212016000074U1 OR NP:DE212016000074U1',
     })
     data = client.search_real(query)
@@ -53,7 +53,7 @@ def depatech_published_data_search_handler(request):
     # Get hold of query expression and filter
     expression = request.params.get('expression', '')
     filter = request.params.get('filter', '')
-    query = SmartBunch({
+    query = SmartMunch({
         'syntax':     'lucene',
         'expression': expression,
         'filter':     filter,
@@ -84,7 +84,7 @@ def depatech_published_data_search_handler(request):
     # - limit
     # - sorting
     # - whether to remove family members
-    options = SmartBunch()
+    options = SmartMunch()
     options.update({
         'limit': limit,
         'offset': offset_remote,
@@ -103,7 +103,7 @@ def depatech_published_data_search_handler(request):
         log.warn(request.errors)
 
     except SyntaxError as ex:
-        request.errors.add('depatech-search', 'expression', unicode(ex.msg))
+        request.errors.add('depatech-search', 'expression', str(ex.msg))
         log.warn(request.errors)
 
     except SearchException as ex:
@@ -117,7 +117,7 @@ def depatech_published_data_search_handler(request):
         return ex.data
 
     except OperationFailure as ex:
-        message = unicode(ex)
+        message = str(ex)
         request.errors.add('depatech-search', 'internals', message)
         log.error(request.errors)
 
@@ -131,7 +131,7 @@ def depatech_published_data_crawl_handler(request):
     """Crawl published-data at MTC depa.tech"""
 
     # Get hold of query expression and filter
-    query = SmartBunch({
+    query = SmartMunch({
         'expression': request.params.get('expression', ''),
         'filter':     request.params.get('filter', ''),
         })
@@ -151,6 +151,6 @@ def depatech_published_data_crawl_handler(request):
         return result
 
     except Exception as ex:
-        request.errors.add('depatech-crawl', 'crawl', unicode(ex))
+        request.errors.add('depatech-crawl', 'crawl', str(ex))
         log.error(request.errors)
-        log.error(u'query="{0}", exception:\n{1}'.format(query, _exception_traceback()))
+        log.error('query="{0}", exception:\n{1}'.format(query, _exception_traceback()))
diff --git a/patzilla/navigator/services/dpma.py b/patzilla/navigator/services/dpma.py
index a83c99bb..9bc363e0 100644
--- a/patzilla/navigator/services/dpma.py
+++ b/patzilla/navigator/services/dpma.py
@@ -94,7 +94,7 @@ def prepare_search(request):
         expression = expression.replace('ikofax:', '')
         syntax = 'ikofax'
 
-    log.info(u'DEPATISnet query: {}, syntax: {}'.format(expression, syntax))
+    log.info('DEPATISnet query: {}, syntax: {}'.format(expression, syntax))
 
     # Compute query options, like
     # - limit
@@ -112,7 +112,7 @@ def prepare_search(request):
     elif syntax == 'ikofax':
         search = ikofax_prepare_query(expression)
     else:
-        request.errors.add('depatisnet-search', 'expression', u'Unknown syntax {}'.format(syntax))
+        request.errors.add('depatisnet-search', 'expression', 'Unknown syntax {}'.format(syntax))
 
     # Propagate keywords to highlighting component
     keywords_to_response(request, search=search)
@@ -165,10 +165,10 @@ def depatisnet_published_data_crawl_handler(request):
         http_response = None
         if hasattr(ex, 'http_response'):
             http_response = ex.http_response
-        log.error(u'DEPATISnet crawler error: query="{0}", reason={1}\nresponse:\n{2}\nexception:\n{3}'.format(
+        log.error('DEPATISnet crawler error: query="{0}", reason={1}\nresponse:\n{2}\nexception:\n{3}'.format(
             query, ex, http_response, _exception_traceback()))
 
-        message = u'An exception occurred while processing your query<br/>Reason: {}'.format(ex)
+        message = 'An exception occurred while processing your query<br/>Reason: {}'.format(ex)
         request.errors.add('depatisnet-search', 'crawl', message)
 
 
diff --git a/patzilla/navigator/services/ificlaims.py b/patzilla/navigator/services/ificlaims.py
index 2897a109..b7ac45ee 100644
--- a/patzilla/navigator/services/ificlaims.py
+++ b/patzilla/navigator/services/ificlaims.py
@@ -18,7 +18,7 @@
 from patzilla.access.ificlaims.api import ificlaims_download, ificlaims_download_multi
 from patzilla.access.ificlaims.client import IFIClaimsException, IFIClaimsFormatException, LoginException, ificlaims_search, ificlaims_crawl, ificlaims_client
 from patzilla.access.ificlaims.expression import should_be_quoted, IFIClaimsParser
-from patzilla.util.data.container import SmartBunch
+from patzilla.util.data.container import SmartMunch
 from patzilla.util.data.zip import zip_multi
 from patzilla.util.python import _exception_traceback
 
@@ -51,7 +51,7 @@
 @status_upstream_ificlaims.get()
 def status_upstream_ificlaims_handler(request):
     client = ificlaims_client()
-    query = SmartBunch({
+    query = SmartMunch({
         'expression': 'pn:EP0666666',
     })
     data = client.search_real(query)
@@ -71,7 +71,7 @@ def ificlaims_download_handler(request):
     try:
         response = ificlaims_download(resource, format, options)
 
-    except IFIClaimsException, ex:
+    except IFIClaimsException as ex:
         if type(ex) is IFIClaimsFormatException:
             raise HTTPNotFound(ex)
         else:
@@ -102,16 +102,16 @@ def ificlaims_deliver_handler(request):
     """Deliver resources from IFI CLAIMS Direct in bulk"""
 
     kind = request.matchdict['kind']
-    formats = map(unicode.strip, request.params.get('formats', u'').lower().split(u','))
-    numberlist = filter(lambda item: bool(item), map(unicode.strip, re.split('[\n,]', request.params.get('numberlist', u''))))
+    formats = list(map(str.strip, request.params.get('formats', '').lower().split(',')))
+    numberlist = [item for item in map(str.strip, re.split('[\n,]', request.params.get('numberlist', ''))) if bool(item)]
 
     if kind == 'zip':
         multi = ificlaims_download_multi(numberlist, formats)
 
         #for entry in multi['results']:
         #    print 'entry:', entry
-        print 'report:'
-        print json.dumps(multi['report'], indent=4)
+        print('report:')
+        print(json.dumps(multi['report'], indent=4))
 
         payload = zip_multi(multi)
 
@@ -138,7 +138,7 @@ def ificlaims_published_data_search_handler(request):
     """Search for published-data at IFI CLAIMS Direct"""
 
     # Get hold of query expression and filter
-    query = SmartBunch({
+    query = SmartMunch({
         'expression': request.params.get('expression', ''),
         'filter':     request.params.get('filter', ''),
     })
@@ -162,7 +162,7 @@ def ificlaims_published_data_search_handler(request):
     # - limit
     # - sorting
     # - whether to remove family members
-    options = SmartBunch()
+    options = SmartMunch()
     options.update({
         'limit': limit,
         'offset': offset_remote,
@@ -181,7 +181,7 @@ def ificlaims_published_data_search_handler(request):
         log.warn(request.errors)
 
     except SyntaxError as ex:
-        request.errors.add('ificlaims-search', 'expression', unicode(ex.msg))
+        request.errors.add('ificlaims-search', 'expression', str(ex.msg))
         log.warn(request.errors)
 
     except SearchException as ex:
@@ -195,7 +195,7 @@ def ificlaims_published_data_search_handler(request):
         return ex.data
 
     except OperationFailure as ex:
-        message = unicode(ex)
+        message = str(ex)
         request.errors.add('ificlaims-search', 'internals', message)
         log.error(request.errors)
 
@@ -209,7 +209,7 @@ def ificlaims_published_data_crawl_handler(request):
     """Crawl published-data at IFI CLAIMS Direct"""
 
     # Get hold of query expression and filter
-    query = SmartBunch({
+    query = SmartMunch({
         'expression': request.params.get('expression', ''),
         'filter':     request.params.get('filter', ''),
         })
@@ -229,6 +229,6 @@ def ificlaims_published_data_crawl_handler(request):
         return result
 
     except Exception as ex:
-        request.errors.add('ificlaims-crawl', 'crawl', unicode(ex))
+        request.errors.add('ificlaims-crawl', 'crawl', str(ex))
         log.error(request.errors)
-        log.error(u'query="{0}", exception:\n{1}'.format(query, _exception_traceback()))
+        log.error('query="{0}", exception:\n{1}'.format(query, _exception_traceback()))
diff --git a/patzilla/navigator/services/ops.py b/patzilla/navigator/services/ops.py
index 08316486..ef9eaf74 100644
--- a/patzilla/navigator/services/ops.py
+++ b/patzilla/navigator/services/ops.py
@@ -89,12 +89,12 @@ def ops_published_data_search_handler(request):
 
     # CQL query string
     query = request.params.get('expression', '')
-    log.info(u'query raw: %s', query)
+    log.info('query raw: %s', query)
 
     # Transcode CQL query expression
     search = cql_prepare_query(query)
 
-    log.info(u'query cql: %s', search.expression)
+    log.info('query cql: %s', search.expression)
 
     # range: x-y, maximum delta is 100, default is 25
     range = request.params.get('range')
@@ -136,7 +136,7 @@ def ops_published_data_crawl_handler(request):
 
     # CQL query string
     query = request.params.get('expression', '')
-    log.info(u'query raw: ' + query)
+    log.info('query raw: ' + query)
 
     # Transcode CQL query expression
     search = cql_prepare_query(query)
@@ -144,7 +144,7 @@ def ops_published_data_crawl_handler(request):
     # Propagate keywords to highlighting component
     keywords_to_response(request, search=search)
 
-    log.info(u'query cql: ' + search.expression)
+    log.info('query cql: ' + search.expression)
 
 
     chunksize = int(request.params.get('chunksize', '100'))
@@ -154,7 +154,7 @@ def ops_published_data_crawl_handler(request):
         return result
 
     except Exception as ex:
-        log.error(u'OPS crawler error: query="{0}", reason={1}, Exception was:\n{2}'.format(query, ex, _exception_traceback()))
+        log.error('OPS crawler error: query="{0}", reason={1}, Exception was:\n{2}'.format(query, ex, _exception_traceback()))
         request.errors.add('ops-published-data-crawl', 'query', str(ex))
 
 
diff --git a/patzilla/navigator/services/util.py b/patzilla/navigator/services/util.py
index 652a78d0..1221fe1f 100644
--- a/patzilla/navigator/services/util.py
+++ b/patzilla/navigator/services/util.py
@@ -5,7 +5,7 @@
 import logging
 import mimetypes
 from pprint import pprint
-from bunch import bunchify
+from munch import munchify
 from cornice.service import Service
 from pyramid.settings import asbool
 from pyramid.threadlocal import get_current_request
@@ -13,7 +13,7 @@
 from patzilla.navigator.export import Dossier, DossierXlsx
 from patzilla.util.config import read_list
 from patzilla.util.cql.util import pair_to_cql
-from patzilla.util.data.container import SmartBunch
+from patzilla.util.data.container import SmartMunch
 from patzilla.util.expression.keywords import keywords_from_boolean_expression
 from patzilla.util.numbers.numberlists import parse_numberlist, normalize_numbers
 from patzilla.util.python import exception_traceback
@@ -55,9 +55,9 @@ def query_expression_util_handler(request):
     # TODO: improve error handling
 
     data = request.json
-    log.info(u'[{userid}] Expression data:  {data}'.format(userid=request.user.userid, data=data))
+    log.info('[{userid}] Expression data:  {data}'.format(userid=request.user.userid, data=data))
     expression_data = make_expression_filter(data)
-    log.info(u'[{userid}] Expression query: {expression_data}'.format(userid=request.user.userid, expression_data=expression_data))
+    log.info('[{userid}] Expression query: {expression_data}'.format(userid=request.user.userid, expression_data=expression_data))
     return expression_data
 
 
@@ -100,7 +100,7 @@ def make_expression_filter(data):
         else:
 
             # Bring criteria in order: Process "fulltext" first
-            keys = criteria.keys()
+            keys = list(criteria.keys())
             if 'fulltext' in keys:
                 keys.remove('fulltext')
                 keys.insert(0, 'fulltext')
@@ -132,7 +132,7 @@ def make_expression_filter(data):
                 elif datasource == 'sip':
                     expression_part = SipExpression.pair_to_sip_xml(key, value, modifiers)
                     if expression_part:
-                        if expression_part.has_key('keywords'):
+                        if 'keywords' in expression_part:
                             keywords += expression_part['keywords']
                         else:
                             keywords += keywords_from_boolean_expression(key, value)
@@ -147,7 +147,7 @@ def make_expression_filter(data):
                     else:
                         expression_part = IFIClaimsExpression.pair_to_solr(key, value, modifiers)
                         if expression_part:
-                            if expression_part.has_key('keywords'):
+                            if 'keywords' in expression_part:
                                 keywords += expression_part['keywords']
                             else:
                                 keywords += keywords_from_boolean_expression(key, value)
@@ -157,13 +157,13 @@ def make_expression_filter(data):
 
                     expression_part = DepaTechExpression.pair_to_elasticsearch(key, value, modifiers)
                     if expression_part:
-                        if expression_part.has_key('keywords'):
+                        if 'keywords' in expression_part:
                             keywords += expression_part['keywords']
                         else:
                             keywords += keywords_from_boolean_expression(key, value)
 
                 # Accumulate expression part
-                error_tpl = u'Criteria "{0}: {1}" has invalid format, datasource={2}.'
+                error_tpl = 'Criteria "{0}: {1}" has invalid format, datasource={2}.'
                 if not expression_part:
                     message = error_tpl.format(key, value, datasource)
                     log.warn(message)
@@ -171,7 +171,7 @@ def make_expression_filter(data):
 
                 elif 'error' in expression_part:
                     message = error_tpl.format(key, value, datasource)
-                    message += u'<br/>' + expression_part['message']
+                    message += '<br/>' + expression_part['message']
                     log.warn(message)
                     request.errors.add('query-expression-utility-service', 'comfort-form', message)
 
@@ -181,12 +181,12 @@ def make_expression_filter(data):
                         expression_parts.append(query)
 
                 # Accumulate filter part
-                error_tpl = u'Filter "{0}: {1}" has invalid format, datasource={2}.'
+                error_tpl = 'Filter "{0}: {1}" has invalid format, datasource={2}.'
                 if filter_part:
 
                     if 'error' in filter_part:
                         message = error_tpl.format(key, value, datasource)
-                        message += u'<br/>' + filter_part['message']
+                        message += '<br/>' + filter_part['message']
                         log.warn(message)
                         request.errors.add('query-expression-utility-service', 'comfort-form', message)
 
@@ -251,8 +251,8 @@ def request_to_options(request, options):
         options.update({'feature_family_replace': True})
 
     # this is awful, switch to JSON POST
-    for key, value in request.params.iteritems():
-        if key.startswith(u'query_data[sorting]'):
+    for key, value in request.params.items():
+        if key.startswith('query_data[sorting]'):
             key = key.replace('query_data[sorting]', '').replace('[', '').replace(']', '')
             options.setdefault('sorting', {})
             options['sorting'][key] = value
@@ -288,7 +288,7 @@ def export_util_handler(request):
     elif output_kind == 'dossier':
 
         log.info('Starting dossier export to format "{format}"'.format(format=output_format))
-        data = bunchify(json.loads(request.params.get('json')))
+        data = munchify(json.loads(request.params.get('json')))
 
         # Debugging
         #print 'dossier-data:'; pprint(data.toDict())
@@ -314,10 +314,10 @@ def export_util_handler(request):
                 payload = dossier.to_zip(request=request, options=data.get('options'))
 
             else:
-                return HTTPBadRequest(u'Export format "{format}" is unknown.'.format(format=output_format))
+                return HTTPBadRequest('Export format "{format}" is unknown.'.format(format=output_format))
 
         except Exception as ex:
-            message = u'Exporting format "{format}" failed.'.format(format=output_format)
+            message = 'Exporting format "{format}" failed.'.format(format=output_format)
             log.error('{message}. Exception:\n{trace}'.format(message=message, trace=exception_traceback()))
             return HTTPServerError(message)
 
@@ -350,7 +350,7 @@ def issue_reporter_handler(request):
 
     report_data = request.json
     report_data.setdefault('application', {})
-    report = SmartBunch.bunchify(report_data)
+    report = SmartMunch.munchify(report_data)
 
     # Add user information to issue report
     user = request.user
@@ -361,7 +361,7 @@ def issue_reporter_handler(request):
         user.upstream_credentials = None
 
         # Serialize user object and attach to report
-        report.application.user = SmartBunch(json.loads(user.to_json()))
+        report.application.user = SmartMunch(json.loads(user.to_json()))
 
     # Send the whole beast to the standard application log
     log.error('Issue report [{targets}]:\n{report}'.format(
diff --git a/patzilla/navigator/settings.py b/patzilla/navigator/settings.py
index 7c809e8a..4f9fc082 100644
--- a/patzilla/navigator/settings.py
+++ b/patzilla/navigator/settings.py
@@ -13,7 +13,8 @@
 from patzilla.util.config import read_list, asbool, get_configuration
 from patzilla.util.date import datetime_isoformat, unixtime_to_datetime
 from patzilla.util.python import _exception_traceback
-from patzilla.util.data.container import SmartBunch
+from patzilla.util.data.container import SmartMunch
+
 
 log = logging.getLogger(__name__)
 
@@ -51,8 +52,7 @@ def get_application_settings(self):
         # TODO: Optimize: Only read once, not on each request!
         # FIXME: Maybe do the same what `attach_ops_client` does?
         #        `if '/static' in event.request.url: return`.
-        settings = get_configuration(self.configfile, kind=SmartBunch)
-
+        settings = get_configuration(self.configfile, kind=SmartMunch)
         # Add some global settings
         settings['software_version'] = __version__
 
@@ -66,10 +66,10 @@ def get_application_settings(self):
     def get_datasource_settings(self, vendor=None):
 
         # Container for datasource settings.
-        datasource_settings = SmartBunch({
+        datasource_settings = SmartMunch({
             'datasources': [],
-            'datasource': SmartBunch(),
-            'total': SmartBunch.bunchify({'fulltext_countries': [], 'details_countries': []}),
+            'datasource': SmartMunch(),
+            'total': SmartMunch.munchify({'fulltext_countries': [], 'details_countries': []}),
         })
 
         # Read datasource settings from configuration.
@@ -77,7 +77,7 @@ def get_datasource_settings(self, vendor=None):
         datasource_settings.protected_fields = read_list(self.application_settings.get('ip_navigator', {}).get('datasources_protected_fields'))
 
         for datasource in datasource_settings.datasources:
-            datasource_info = SmartBunch()
+            datasource_info = SmartMunch()
             if vendor is None:
                 settings_key = 'datasource:{name}'.format(name=datasource)
             else:
@@ -88,10 +88,10 @@ def get_datasource_settings(self, vendor=None):
             datasource_info.setdefault('fulltext_countries', read_list(ds_settings.get('fulltext_countries', '')))
             datasource_info.setdefault('details_enabled', asbool(ds_settings.get('details_enabled', False)))
             datasource_info.setdefault('details_countries', read_list(ds_settings.get('details_countries', '')))
-            for key, value in ds_settings.iteritems():
+            for key, value in ds_settings.items():
                 datasource_info.setdefault(key, value)
 
-            datasource_settings.datasource[datasource] = SmartBunch.bunchify(datasource_info)
+            datasource_settings.datasource[datasource] = SmartMunch.munchify(datasource_info)
 
             # Aggregate data for all countries.
             datasource_settings.total.fulltext_countries += datasource_info['fulltext_countries']
@@ -101,9 +101,9 @@ def get_datasource_settings(self, vendor=None):
     def get_vendor_settings(self):
 
         # Container for vendor settings
-        vendor_settings = SmartBunch({
+        vendor_settings = SmartMunch({
             'vendors': [],
-            'vendor': SmartBunch(),
+            'vendor': SmartMunch(),
         })
 
         # Read vendor settings from configuration
@@ -122,8 +122,8 @@ def get_vendor_settings(self):
                     vendor=vendor, configfile=self.configfile))
 
             vendor_info = self.application_settings.get(settings_key, {})
-            for key, value in vendor_info.iteritems():
-                vendor_info[key] = value.decode('utf-8')
+            for key, value in vendor_info.items():
+                vendor_info[key] = value
 
             if 'hostname_matches' in vendor_info:
                 vendor_info.hostname_matches = read_list(vendor_info.hostname_matches)
@@ -135,7 +135,7 @@ def get_vendor_settings(self):
             vendor_info.datasource_settings = self.get_datasource_settings(vendor)
 
             # Collect all vendor settings.
-            vendor_settings.vendor[vendor] = SmartBunch.bunchify(vendor_info)
+            vendor_settings.vendor[vendor] = SmartMunch.munchify(vendor_info)
 
         return vendor_settings
 
@@ -146,9 +146,9 @@ def get_email_settings(self, vendor):
         """
 
         # Container for email settings
-        email_settings = SmartBunch({
+        email_settings = SmartMunch({
             'addressbook': [],
-            'content': SmartBunch(),
+            'content': SmartMunch(),
         })
 
         for setting_name in ['addressbook', 'content']:
@@ -160,8 +160,8 @@ def get_email_settings(self, vendor):
             if defaults and specific:
                 thing.update(deepcopy(specific))
 
-            for key, value in thing.items():
-                thing[key] = value.decode('utf-8')
+            for key, value in list(thing.items()):
+                thing[key] = value
 
             email_settings[setting_name] = thing
 
@@ -227,7 +227,7 @@ def effective_vendor(self):
 
         # Skip resolving effective vendor when no vendors are configured at all
         if self.registry.vendor_settings is None:
-            return SmartBunch()
+            return SmartMunch()
 
         # Select vendor by matching hostnames
         vendor_names = self.registry.vendor_settings.vendors
@@ -281,12 +281,12 @@ def theme_settings(self):
             'ui.version': software_version_link,
             'ui.page.title': vendor.get('page_title', ''), # + ' &nbsp; ' + self.beta_badge,
             'ui.page.subtitle': '',
-            'ui.page.footer': 'Data sources: ' + u', '.join(data_source_list),
+            'ui.page.footer': 'Data sources: ' + ', '.join(data_source_list),
         }
 
         # Transfer all properties having designated prefixes 1:1
         prefixes = ['ui.', 'feature.']
-        for key, value in vendor.iteritems():
+        for key, value in vendor.items():
             for prefix in prefixes:
                 if key.startswith(prefix):
                     if key.endswith('.enabled'):
@@ -304,10 +304,10 @@ def datasource_settings(self):
         Return datasource settings while accounting for sensible settings like API URI and credentials.
         """
         request = get_current_request()
-        datasource_settings = SmartBunch.bunchify(request.registry.datasource_settings)
+        datasource_settings = SmartMunch.munchify(request.registry.datasource_settings)
         if 'protected_fields' in datasource_settings:
             for fieldname in datasource_settings.protected_fields:
-                for name, settings in datasource_settings.datasource.iteritems():
+                for name, settings in datasource_settings.datasource.items():
                     if fieldname in settings:
                         del settings[fieldname]
             del datasource_settings['protected_fields']
@@ -363,7 +363,7 @@ def config_parameters(self):
         isviewer = 'patentview' in host or 'viewer' in host or 'patview' in host
 
         # 1. don't allow "query" from outside on view-only domains
-        if request_params.has_key('query') and isviewer:
+        if 'query' in request_params and isviewer:
             log.warning('Parameter "query=%s" not allowed on host "%s", purging it', request_params['query'], host)
             del request_params['query']
 
@@ -388,7 +388,7 @@ def config_parameters(self):
         # C. parameter firewall, OUTPUT
 
         # remove "opaque parameter"
-        if params.has_key('op'):
+        if 'op' in params:
             del params['op']
 
 
@@ -409,7 +409,7 @@ def config_parameters(self):
                 params['datasources_enabled'].append(datasource)
 
         # E. backward-compat amendments
-        for key, value in params.iteritems():
+        for key, value in params.items():
             if key.startswith('ship_'):
                 newkey = key.replace('ship_', 'ship-')
                 params[newkey] = value
diff --git a/patzilla/navigator/tools/browser_database_tool.py b/patzilla/navigator/tools/browser_database_tool.py
index 98e4c8f8..ec1bc5ab 100755
--- a/patzilla/navigator/tools/browser_database_tool.py
+++ b/patzilla/navigator/tools/browser_database_tool.py
@@ -12,17 +12,17 @@
 
 def purge_titles(data):
     # Purge "title" attributes from BasketEntry objects
-    for name, entity in data['database'].iteritems():
+    for name, entity in data['database'].items():
         if name.startswith('BasketEntry'):
             if 'title' in entity:
                 del entity['title']
             if 'number' in entity:
-                entity['number'] = entity['number'].strip(u'★ ')
+                entity['number'] = entity['number'].strip('★ ')
 
 def purge_numbers_seen(data):
     # Purge all BasketEntry objects with "seen==true"
     keys = []
-    for name, item in data['database'].iteritems():
+    for name, item in data['database'].items():
         if name.startswith('BasketEntry/'):
             if 'seen' in item and item['seen'] == True:
                 keys.append(name)
@@ -32,7 +32,7 @@ def purge_numbers_seen(data):
 
 def purge_projects(data):
     # Purge "project" attributes from all "Query/..." objects
-    for name, item in data['database'].iteritems():
+    for name, item in data['database'].items():
         if name.startswith('Query/'):
             if 'project' in item:
                 del item['project']
@@ -51,7 +51,7 @@ def main():
     #purge_projects(data)
 
     # Save database file
-    print json.dumps(data, indent=4)
+    print(json.dumps(data, indent=4))
 
 
 if __name__ == '__main__':
diff --git a/patzilla/navigator/util.py b/patzilla/navigator/util.py
index ad77fc2f..df5314a4 100644
--- a/patzilla/navigator/util.py
+++ b/patzilla/navigator/util.py
@@ -6,7 +6,7 @@
 
 def get_exception_message(ex, add_traceback=False):
     name = ex.__class__.__name__
-    description = '%s: %s' % (name, unicode(ex.message))
+    description = '%s: %s' % (name, str(ex.message))
     if add_traceback:
         description += '\n' + get_safe_traceback(ex)
     return description
@@ -24,7 +24,7 @@ def safe_value(value):
     e.g. CaseInsensitiveDict to dict
     """
     if hasattr(value, 'items') and callable(value.items):
-        return dict(value.items())
+        return dict(list(value.items()))
     else:
         return value
 
@@ -35,7 +35,7 @@ def dict_subset(bigdict, *wanted_keys):
 def dict_prefix_key(d, prefix):
     # prefix keys in dictionary
     new = {}
-    for key, value in d.iteritems():
+    for key, value in d.items():
         key = prefix + key
         new[key] = value
     return new
@@ -53,7 +53,7 @@ def dict_merge(dct, merge_dct):
     :param merge_dct: dct merged into dct
     :return: None
     """
-    for k, v in merge_dct.iteritems():
+    for k, v in merge_dct.items():
         if (k in dct and isinstance(dct[k], dict)
             and isinstance(merge_dct[k], collections.Mapping)):
             dict_merge(dct[k], merge_dct[k])
diff --git a/patzilla/navigator/views.py b/patzilla/navigator/views.py
index 36050c9b..0389bb7e 100644
--- a/patzilla/navigator/views.py
+++ b/patzilla/navigator/views.py
@@ -137,7 +137,7 @@ def navigator_quick(request):
 
     # Compute query expression
     expression = compute_expression(field, value, value2, parameters=request.params)
-    print 'quick expression:', expression
+    print('quick expression:', expression)
 
     #return get_redirect_query(request, expression, query_args=query_args)
     return get_redirect_query(request, expression)
@@ -150,7 +150,7 @@ def compute_expression(field, value, value2=None, **kwargs):
         field = 'pn'
 
     if field in ['cl', 'ipc', 'ic', 'cpc', 'cpci', 'cpca']:
-        value = value.replace(u'-', u'/')
+        value = value.replace('-', '/')
 
     quotable = True
     if field in ['pa', 'applicant']:
@@ -159,38 +159,38 @@ def compute_expression(field, value, value2=None, **kwargs):
 
             # apply blacklist
             blacklist = [
-                u'GmbH & Co. KG',
-                u'GmbH',
-                u' KG',
-                u' AG',
-                u'& Co.',
+                'GmbH & Co. KG',
+                'GmbH',
+                ' KG',
+                ' AG',
+                '& Co.',
             ]
             replacements = {
-                u' and ': u' ',
-                u' or ':  u' ',
-                u' not ': u' ',
+                ' and ': ' ',
+                ' or ':  ' ',
+                ' not ': ' ',
             }
             for black in blacklist:
                 pattern = re.compile(re.escape(black), re.IGNORECASE)
-                value = pattern.sub(u'', value).strip()
-            for replacement_key, replacement_value in replacements.iteritems():
+                value = pattern.sub('', value).strip()
+            for replacement_key, replacement_value in replacements.items():
                 #value = value.replace(replacement_key, replacement_value)
                 pattern = re.compile(replacement_key, re.IGNORECASE)
                 value = pattern.sub(replacement_value, value).strip()
 
             # make query expression
-            parts_raw = re.split(u'[ -]*', value)
+            parts_raw = re.split('[ -]*', value)
             umlaut_map = {
-                u'ä': u'ae',
-                u'ö': u'oe',
-                u'ü': u'ue',
-                u'Ä': u'Ae',
-                u'Ö': u'Oe',
-                u'Ü': u'Ue',
-                u'ß': u'ss',
+                'ä': 'ae',
+                'ö': 'oe',
+                'ü': 'ue',
+                'Ä': 'Ae',
+                'Ö': 'Oe',
+                'Ü': 'Ue',
+                'ß': 'ss',
             }
             def replace_parts(thing):
-                for umlaut, replacement in umlaut_map.iteritems():
+                for umlaut, replacement in umlaut_map.items():
                     thing = thing.replace(umlaut, replacement)
                 return thing
 
@@ -198,22 +198,22 @@ def replace_parts(thing):
             for part in parts_raw:
 
                 # "Alfred H. Schütte" => Alfred Schütte
-                if re.match(u'^(\w\.)+$', part):
+                if re.match('^(\w\.)+$', part):
                     continue
 
                 part_normalized = replace_parts(part)
                 if part != part_normalized:
-                    part = u'({} or {})'.format(part, part_normalized)
+                    part = '({} or {})'.format(part, part_normalized)
                 parts.append(part)
 
-            value = u' and '.join(parts)
+            value = ' and '.join(parts)
             #value = u'({})'.format(value)
 
 
-    if quotable and u' ' in value:
-        value = u'"{0}"'.format(value)
+    if quotable and ' ' in value:
+        value = '"{0}"'.format(value)
 
-    query = u'{field}={value}'.format(**locals())
+    query = '{field}={value}'.format(**locals())
 
     if field in ['pd', 'publicationdate']:
         if 'W' in value:
diff --git a/patzilla/util/config/__init__.py b/patzilla/util/config/__init__.py
index 0c94ff3a..e332bccb 100644
--- a/patzilla/util/config/__init__.py
+++ b/patzilla/util/config/__init__.py
@@ -4,7 +4,7 @@
 import logging
 import sys
 from glob import glob
-from ConfigParser import ConfigParser
+from configparser import ConfigParser
 
 logger = logging.getLogger(__name__)
 
@@ -29,7 +29,7 @@ def get_configuration(*args, **kwargs):
         logger.info('Effective configuration files: {}'.format(make_list(used)))
         return config
     else:
-        msg = u'Could not read settings from configuration files: {}'.format(config_files)
+        msg = 'Could not read settings from configuration files: {}'.format(config_files)
         logger.critical(msg)
         raise ValueError(msg)
 
@@ -76,22 +76,22 @@ def asbool(s):
     s = str(s).strip()
     return s.lower() in truthy
 
-def read_list(string, separator=u','):
+def read_list(string, separator=','):
     if string is None:
         return []
     elif isinstance(string, list):
         return string
-    result = map(unicode.strip, string.split(separator))
+    result = list(map(str.strip, string.split(separator)))
     if len(result) == 1 and not result[0]:
         result = []
     return result
 
-def make_list(items, separator=u', '):
+def make_list(items, separator=', '):
     return separator.join(items)
 
 def normalize_docopt_options(options):
     normalized = {}
-    for key, value in options.items():
+    for key, value in list(options.items()):
         key = key.strip('--<>')
         normalized[key] = value
     return normalized
diff --git a/patzilla/util/cql/cheshire3/__init__.py b/patzilla/util/cql/cheshire3/__init__.py
index 35e47286..aad5781f 100644
--- a/patzilla/util/cql/cheshire3/__init__.py
+++ b/patzilla/util/cql/cheshire3/__init__.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # (c) 2014 Andreas Motl, Elmyra UG <andreas.motl@elmyra.de>
-import parser as cheshire3_parser
-from parser import SearchClause, CQLParser, Diagnostic
+from . import parser as cheshire3_parser
+from .parser import SearchClause, CQLParser, Diagnostic
 from patzilla.util.numbers.normalize import normalize_patent
 
 
@@ -14,7 +14,7 @@ class SmartSearchClause(SearchClause):
     def toCQL(self):
 
         text = []
-        for p in self.prefixes.keys():
+        for p in list(self.prefixes.keys()):
             if (p != ''):
                 text.append('>%s="%s"' % (p, self.prefixes[p]))
             else:
diff --git a/patzilla/util/cql/cheshire3/parser.py b/patzilla/util/cql/cheshire3/parser.py
index 15504717..610af8e9 100644
--- a/patzilla/util/cql/cheshire3/parser.py
+++ b/patzilla/util/cql/cheshire3/parser.py
@@ -19,8 +19,8 @@
 
 from shlex import shlex
 from xml.sax.saxutils import escape
-from StringIO import StringIO
-from __builtin__ import isinstance
+from io import StringIO
+from builtins import isinstance
 
 serverChoiceRelation = "="
 serverChoiceIndex = "cql.serverchoice"
@@ -75,7 +75,7 @@ def __init__(self):
     def toXCQL(self, depth=0):
         space = "  " * depth
         xml = ['{s}<prefixes>\n']
-        for p in self.prefixes.keys():
+        for p in list(self.prefixes.keys()):
             xml.extend(["{s}  <prefix>\n",
                         "{s}    <name>{name}</name>\n",
                         "{s}    <identifier>{ident}</identifier>\n",
@@ -221,7 +221,7 @@ def toCQL(self):
         txt = []
         if (self.prefixes):
             ptxt = []
-            for p in self.prefixes.keys():
+            for p in list(self.prefixes.keys()):
                 if p != '':
                     ptxt.append('>%s="%s"' % (p, self.prefixes[p]))
                 else:
@@ -236,7 +236,7 @@ def toCQL(self):
             txt.append("sortBy")
             for sk in self.sortKeys:
                 txt.append(sk.toCQL())
-        return u"({0})".format(u" ".join(txt))
+        return "({0})".format(" ".join(txt))
 
     def getResultSetId(self, top=None):
         if (
@@ -315,7 +315,7 @@ def toXCQL(self, depth=0):
 
     def toCQL(self):
         text = []
-        for p in self.prefixes.keys():
+        for p in list(self.prefixes.keys()):
             if p != '':
                 text.append('>%s="%s"' % (p, self.prefixes[p]))
             else:
@@ -406,7 +406,7 @@ def toXCQL(self, depth=0):
 
     def toCQL(self):
         txt = [self.value]
-        txt.extend(map(str, self.modifiers))
+        txt.extend(list(map(str, self.modifiers)))
         return '/'.join(txt)
 
 
@@ -572,7 +572,6 @@ def __init__(self, thing):
         shlex.__init__(self, thing)
         self.wordchars += "!@#$%^&*-+{}[];,.?|~`:\\"
         # self.wordchars += ''.join(map(chr, range(128,254)))
-        self.wordchars = self.wordchars.decode('utf-8')
 
     def read_token(self):
         "Read a token from the input stream (no pushback or inclusions)"
@@ -774,7 +773,7 @@ def query(self):
                 left.sortKeys = self.sortQuery()
             else:
                 break
-        for p in prefs.keys():
+        for p in list(prefs.keys()):
             left.addPrefix(p, prefs[p])
         return left
 
@@ -812,7 +811,7 @@ def subQuery(self):
             prefs = self.prefixes()
             if (prefs):
                 object = self.query()
-                for p in prefs.keys():
+                for p in list(prefs.keys()):
                     object.addPrefix(p, prefs[p])
             else:
                 object = self.clause()
@@ -847,7 +846,7 @@ def clause(self):
         elif self.currentToken == ">":
             prefs = self.prefixes()
             object = self.clause()
-            for p in prefs.keys():
+            for p in list(prefs.keys()):
                 object.addPrefix(p, prefs[p])
             return object
 
@@ -915,12 +914,6 @@ def relation(self):
 def parse(query):
     """Return a searchClause/triple object from CQL string"""
 
-    if type(query) == str:
-        try:
-            query = query.decode("utf-8")
-        except Exception, e:
-            raise
-
     q = StringIO(query)
     lexer = CQLshlex(q)
     parser = CQLParser(lexer)
diff --git a/patzilla/util/cql/cheshire3/test_cheshire3.py b/patzilla/util/cql/cheshire3/test_cheshire3.py
index daab7bb1..89020576 100644
--- a/patzilla/util/cql/cheshire3/test_cheshire3.py
+++ b/patzilla/util/cql/cheshire3/test_cheshire3.py
@@ -54,13 +54,13 @@ def test_value_shortcut_notation_fail(self):
             self.do_parse('ti=(foo and bar baz) and pc=qux')
         self.assertEqual(
             str(cm.exception),
-            "info:srw/diagnostic/1/10 [Malformed Query]: Expected Boolean or closing parenthesis but got: u'baz'")
+            "info:srw/diagnostic/1/10 [Malformed Query]: Expected Boolean or closing parenthesis but got: 'baz'")
 
     def test_boolean_german(self):
         self.assertEqual(self.do_parse('bi=foo und bi=bar'), '(bi = "foo" und bi = "bar")')
 
     def test_utf8(self):
-        self.assertEqual(self.do_parse('ab=radaufstandskraft or ab=radaufstandskräfte?'), u'(ab = "radaufstandskraft" or ab = "radaufstandskr\xe4fte?")')
+        self.assertEqual(self.do_parse('ab=radaufstandskraft or ab=radaufstandskräfte?'), '(ab = "radaufstandskraft" or ab = "radaufstandskr\xe4fte?")')
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/patzilla/util/cql/pyparsing/__init__.py b/patzilla/util/cql/pyparsing/__init__.py
index f916d5aa..9bf78eda 100644
--- a/patzilla/util/cql/pyparsing/__init__.py
+++ b/patzilla/util/cql/pyparsing/__init__.py
@@ -45,7 +45,7 @@ def parse(self):
 
         >>> tokens = parse_cql('foo=bar')
         >>> tokens
-        ([(['foo', u'=', 'bar'], {'triple': [((['foo', u'=', 'bar'], {}), 0)]})], {})
+        ParseResults([ParseResults(['foo', '=', 'bar'], {'triple': ['foo', '=', 'bar']})], {})
 
         """
 
@@ -60,13 +60,13 @@ def parse(self):
             #if self.logging:
             #    log.info(u'tokens: %s', tokens.pformat())
 
-        except pyparsing.ParseException as ex:
-            ex.explanation = u'%s\n%s\n%s' % (ex.pstr, u' ' * ex.loc + u'^\n', ex)
+        except pyparsing.exceptions.ParseException as ex:
+            ex.explanation = '%s\n%s\n%s' % (ex.pstr, ' ' * ex.loc + '^\n', ex)
             #if self.logging:
             #    log.error('\n%s', ex.explanation)
-            log.warning(u'Query expression "{query}" is invalid. ' \
-                        u'Reason: {reason}\n{location}'.format(
-                query=self.cql, reason=unicode(ex), location=ex.explanation))
+            log.warning('Query expression "{query}" is invalid. ' \
+                        'Reason: {reason}\n{location}'.format(
+                query=self.cql, reason=str(ex), location=ex.explanation))
             raise
 
         return tokens
diff --git a/patzilla/util/cql/pyparsing/demo.py b/patzilla/util/cql/pyparsing/demo.py
index 47573044..157773c6 100644
--- a/patzilla/util/cql/pyparsing/demo.py
+++ b/patzilla/util/cql/pyparsing/demo.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # (c) 2014 Andreas Motl, Elmyra UG
 from . import CQL
-from serializer import tokens_to_cql, expand_shortcut_notation, get_triples, get_keywords, normalize_patentnumbers
+from .serializer import tokens_to_cql, expand_shortcut_notation, get_triples, get_keywords, normalize_patentnumbers
 
 def parse_cql(cql):
     c = CQL(cql)
@@ -24,9 +24,9 @@ def enrich_cql(cql):
 
 def dump_results(tokens):
     cql = tokens_to_cql(tokens)
-    print "=" * 42
-    print "tokens:", tokens
-    print "cql:", cql
+    print("=" * 42)
+    print("tokens:", tokens)
+    print("cql:", cql)
 
 
 def rundemo():
@@ -80,11 +80,11 @@ def rundemo():
         # B.3. dump all triples
         triples = []
         get_triples(tokens, triples)
-        print "triples:", triples
+        print("triples:", triples)
 
         # B.4. dump all keywords
         keywords = get_keywords(triples)
-        print "keywords:", keywords
+        print("keywords:", keywords)
 
 
 if __name__ == '__main__':
diff --git a/patzilla/util/cql/pyparsing/parser.py b/patzilla/util/cql/pyparsing/parser.py
index 12c6cfb2..5ab35363 100644
--- a/patzilla/util/cql/pyparsing/parser.py
+++ b/patzilla/util/cql/pyparsing/parser.py
@@ -21,11 +21,10 @@
     Keyword, CaselessKeyword, \
     Regex, \
     alphas, nums, alphanums, quotedString, \
-    oneOf, upcaseTokens, delimitedList, restOfLine, \
+    oneOf, common, delimitedList, restOfLine, \
     Forward, Group, Combine, Optional, ZeroOrMore, OneOrMore, \
     NotAny, Suppress, FollowedBy, StringEnd, \
     ParseResults, ParseException, removeQuotes
-from patzilla.util.cql.pyparsing.util import get_literals
 
 
 log = logging.getLogger(__name__)
@@ -54,19 +53,19 @@
 
 TODO: maybe extract this to a different place, since ..services is also using it
 """
-wildcards = u'*?#!'
+wildcards = '*?#!'
 
 # - classification terms (IPC, CPC) may contain forward slashes and dashes, e.g. H04L12/433, F17D5-00
 # - numeric terms may contain punctuation (,.), e.g. 2.45
 # - dates may contain dashes, e.g. M11-2009
-separators = u'/,.-'
+separators = '/,.-'
 
 # limited set of unicode characters
 #umlauts = u'äöüÄÖÜß'
 
 # all unicode characters
 # http://stackoverflow.com/questions/2339386/python-pyparsing-unicode-characters/2340659#2340659
-unicode_printables = u''.join(unichr(c) for c in xrange(65536) if unichr(c).isalnum() and not unichr(c).isspace())
+unicode_printables = ''.join(chr(c) for c in range(65536) if chr(c).isalnum() and not chr(c).isspace())
 
 # indexchars
 indexchars = alphanums + '{}!'
@@ -92,16 +91,17 @@ def __init__(self):
     def preconfigure(self):
 
         # Binary comparison operators
-        self.cmp_single = u'= != < > <= >='.split()
-        self.cmp_perl = u'eq ne lt gt le ge'.split()
-        self.cmp_cql = u'exact within encloses all any any/relevant any/rel.lr'.split()
+        self.cmp_single = '= != < > <= >='.split()
+        self.cmp_perl = 'eq ne lt gt le ge'.split()
+        self.cmp_cql = 'exact within encloses all any any/relevant any/rel.lr'.split()
 
         # Boolean operators
         # TODO: Configure german operators with DPMAGrammar only
-        self.and_ = CaselessKeyword("and") | CaselessKeyword("UND")
-        self.or_ = CaselessKeyword("or") | CaselessKeyword("ODER")
-        self.not_ = CaselessKeyword("not") | CaselessKeyword("NICHT")
-        self.prox_ = CaselessKeyword("prox") | CaselessKeyword("NAHE")
+        self.booleans = ("and", "UND", "or", "ODER", "not", "NICHT", "prox", "NAHE")
+        self.and_ = CaselessKeyword(self.booleans[0]) | CaselessKeyword(self.booleans[1])
+        self.or_ = CaselessKeyword(self.booleans[2]) | CaselessKeyword(self.booleans[3])
+        self.not_ = CaselessKeyword(self.booleans[4]) | CaselessKeyword(self.booleans[5])
+        self.prox_ = CaselessKeyword(self.booleans[6]) | CaselessKeyword(self.booleans[7])
 
         # Neighbourhood term operators
         self.neighbourhood_symbols = '(W) (NOTW) (#W) (A) (#A) (P) (L)'.split()
@@ -112,7 +112,6 @@ def configure(self):
         self.binop_symbols = self.cmp_single + self.cmp_perl + self.cmp_cql
 
         # Boolean operators
-        self.booleans    = get_literals(self.and_, self.or_, self.not_, self.prox_)
         self.booleans_or = ( self.and_ | self.or_ | self.not_ | self.prox_ )
 
         # Neighbourhood term operators
@@ -134,7 +133,7 @@ def build(self):
         # ------------------------------------------
         #   C. building blocks
         # ------------------------------------------
-        self.termop = Regex( "|".join(self.neighbourhood_symbols), re.IGNORECASE ).setParseAction( upcaseTokens ).setName("termop")
+        self.termop = Regex( "|".join(self.neighbourhood_symbols), re.IGNORECASE ).setParseAction( common.upcase_tokens ).setName("termop")
         termword = Word(self.unicode_printables + self.separators + self.wildcards).setName("term")
         termword_termop = (termword + OneOrMore( self.termop + termword ))
 
diff --git a/patzilla/util/cql/pyparsing/searchparser.py b/patzilla/util/cql/pyparsing/searchparser.py
index 880ebad1..e4b26ae1 100644
--- a/patzilla/util/cql/pyparsing/searchparser.py
+++ b/patzilla/util/cql/pyparsing/searchparser.py
@@ -65,18 +65,27 @@
    Set = set
 except NameError:
    from sets import Set
+
 from patzilla.util.cql.pyparsing.parser import separators, wildcards
 
+import sys
+_IS_PYTHON_3 = (sys.version_info[0] >= 3)
+if _IS_PYTHON_3:
+    Set = set
+else:
+    from sets import Set
+
 # define characters comprising a word
 #wordchars = alphanums + separators + wildcards
 
 # all unicode characters
 # http://stackoverflow.com/questions/2339386/python-pyparsing-unicode-characters/2340659#2340659
-unicode_printables = u''.join(unichr(c) for c in xrange(65536) if unichr(c).isalnum() and not unichr(c).isspace())
-more_chars = u'°'
+unicode_printables = ''.join(chr(c) for c in range(65536) if chr(c).isalnum() and not chr(c).isspace())
+more_chars = '°'
 wordchars = unicode_printables + more_chars + separators + wildcards
 
 
+
 class SearchQueryParser:
 
     def __init__(self):
@@ -272,14 +281,14 @@ class ParserTest(SearchQueryParser):
         }
 
     def GetWord(self, word):
-        if (self.index.has_key(word)):
+        if (word in self.index):
             return self.index[word]
         else:
             return Set()
 
     def GetWordWildcard(self, word):
         result = Set()
-        for item in self.index.keys():
+        for item in list(self.index.keys()):
             if word == item[0:len(word)]:
                 result = result.union(self.index[item])
         return result
@@ -292,27 +301,27 @@ def GetQuotes(self, search_string, tmp_result):
         return result
 
     def GetNot(self, not_set):
-        all = Set(self.docs.keys())
+        all = Set(list(self.docs.keys()))
         return all.difference(not_set)
 
     def Test(self):
         all_ok = True
-        for item in self.tests.keys():
-            print item
+        for item in list(self.tests.keys()):
+            print(item)
             r = self.Parse(item)
             e = self.tests[item]
-            print 'Result: %s' % r
-            print 'Expect: %s' % e
+            print('Result: %s' % r)
+            print('Expect: %s' % e)
             if e == r:
-                print 'Test OK'
+                print('Test OK')
             else:
                 all_ok = False
-                print '>>>>>>>>>>>>>>>>>>>>>>Test ERROR<<<<<<<<<<<<<<<<<<<<<'
-            print ''
+                print('>>>>>>>>>>>>>>>>>>>>>>Test ERROR<<<<<<<<<<<<<<<<<<<<<')
+            print('')
         return all_ok
 
 if __name__=='__main__':
     if ParserTest().Test():
-        print 'All tests OK'
+        print('All tests OK')
     else:
-        print 'One or more tests FAILED'
\ No newline at end of file
+        print('One or more tests FAILED')
diff --git a/patzilla/util/cql/pyparsing/serializer.py b/patzilla/util/cql/pyparsing/serializer.py
index a078b5f8..3abe241b 100644
--- a/patzilla/util/cql/pyparsing/serializer.py
+++ b/patzilla/util/cql/pyparsing/serializer.py
@@ -3,7 +3,7 @@
 import re
 import types
 import logging
-import StringIO
+import io
 from pyparsing import ParseResults
 from patzilla.util.cql.pyparsing.parser import CQLGrammar
 from patzilla.util.cql.pyparsing.util import walk_token_results, token_to_triple
@@ -29,10 +29,10 @@ def tokens_to_cql(tokens):
 
     >>> tokens = parse_cql('foo=bar and baz=(qux or quux)')
     >>> tokens_to_cql(tokens)
-    u'foo=bar and baz=(qux or quux)'
+    'foo=bar and baz=(qux or quux)'
 
     """
-    buffer = StringIO.StringIO()
+    buffer = io.StringIO()
     tokens_to_cql_buffer(tokens, buffer)
     buffer.seek(0)
     return buffer.read()
@@ -51,23 +51,23 @@ def tokens_to_cql_buffer(tokens, buffer):
 
                     # surround binop with spaces for all operators but equality (=)
                     if binop != '=':
-                        triple[1] = u' {0} '.format(binop)
+                        triple[1] = ' {0} '.format(binop)
 
-                    payload = u''.join(triple)
+                    payload = ''.join(triple)
 
                 else:
-                    payload = u''.join(token)
+                    payload = ''.join(token)
 
                 buffer.write(payload)
 
             elif name.startswith('subquery'):
                 tokens_to_cql_buffer(token, buffer)
 
-        elif tokentype in types.StringTypes:
+        elif tokentype in (str,):
             out = token
             # surround all boolean operators with whitespace
             if token in grammar.booleans:
-                out = u' {0} '.format(token)
+                out = ' {0} '.format(token)
             buffer.write(out)
 
 def normalize_patentnumbers(tokens):
@@ -77,7 +77,7 @@ def normalize_patentnumbers(tokens):
     >>> tokens = parse_cql('pn=EP666666')
     >>> normalize_patentnumbers(tokens)
     >>> tokens_to_cql(tokens)
-    u'pn=EP0666666'
+    'pn=EP0666666'
 
     """
     def action(token, index, binop, term):
@@ -99,15 +99,15 @@ def get_keywords(triples, whitelist_indexes=None):
 
     >>> triples = []; get_triples(parse_cql('txt=foo or (bi=bar or bi=baz)'), triples)
     >>> get_keywords(triples)
-    [u'foo', u'bar', u'baz']
+    ['foo', 'bar', 'baz']
 
     >>> triples = []; get_triples(parse_cql('pa all "central, intelligence, agency"'), triples)
     >>> get_keywords(triples)
-    [u'central', u'intelligence', u'agency']
+    ['central', 'intelligence', 'agency']
 
     >>> triples = []; get_triples(parse_cql('foo=bar and baz=qux'), triples)
     >>> get_keywords(triples, ['baz'])
-    [u'qux']
+    ['qux']
 
     """
     keywords = []
@@ -143,11 +143,11 @@ def trim_keywords(keywords):
       keywords and a list of keyword elements for multi-term keywords
 
     Example:
-    >>> trim_keywords([u'!!!daimler?', u'Misch?(P)?wasser'])
-    [u'daimler', [u'Misch', u'wasser']]
+    >>> trim_keywords(['!!!daimler?', 'Misch?(P)?wasser'])
+    ['daimler', ['Misch', 'wasser']]
 
-    >>> trim_keywords([u'"foo"', u'"   bar   "'])
-    [u'foo', u'bar']
+    >>> trim_keywords(['"foo"', '"   bar   "'])
+    ['foo', 'bar']
 
     """
     keywords_trimmed = []
@@ -164,7 +164,7 @@ def get_triples(tokens, triples):
 
     >>> triples = []; get_triples(parse_cql('foo=bar and baz=(qux or quux)'), triples)
     >>> triples
-    [['foo', u'=', 'bar'], ['qux'], ['quux']]
+    [['foo', '=', 'bar'], ['qux'], ['quux']]
 
     """
     for token in tokens:
@@ -184,7 +184,7 @@ def expand_shortcut_notation(tokens, index=None, binop=None):
     >>> tokens = parse_cql('foo=bar and baz=(qux or quux)')
     >>> expand_shortcut_notation(tokens)
     >>> tokens_to_cql(tokens)
-    u'foo=bar and (baz=qux or baz=quux)'
+    'foo=bar and (baz=qux or baz=quux)'
 
     """
     for token in tokens:
@@ -200,7 +200,7 @@ def expand_shortcut_notation(tokens, index=None, binop=None):
                 # If it does, put term inside parenthesis, which got lost while performing shortcut expansion.
                 if token:
                     if re.match('.*(?:' + grammar.termop.pattern + ').*', token[0], flags=grammar.termop.flags):
-                        token[0] = u'({0})'.format(token[0])
+                        token[0] = '({0})'.format(token[0])
 
                 # Process triple in value shortcut notation (contains only the single term).
                 # Take action: Insert index and binop from subquery context.
diff --git a/patzilla/util/cql/pyparsing/test/01_spec.rst b/patzilla/util/cql/pyparsing/test/01_spec.rst
index de7571ed..a5395600 100644
--- a/patzilla/util/cql/pyparsing/test/01_spec.rst
+++ b/patzilla/util/cql/pyparsing/test/01_spec.rst
@@ -20,52 +20,52 @@ Simple queries
 ==============
 
 >>> CQL('dinosaur').dumps()
-u'dinosaur'
+'dinosaur'
 
 >>> CQL('"complete dinosaur"').dumps()
-u'"complete dinosaur"'
+'"complete dinosaur"'
 
 >>> CQL('title = "complete dinosaur"').dumps()
-u'title="complete dinosaur"'
+'title="complete dinosaur"'
 
 >>> CQL('title exact "the complete dinosaur"').dumps()
-u'title exact "the complete dinosaur"'
+'title exact "the complete dinosaur"'
 
 
 Queries using Boolean logic
 ===========================
 
 >>> CQL('dinosaur or bird').dumps()
-u'dinosaur or bird'
+'dinosaur or bird'
 
 .. note:: **FIXME: enhance grammar**
 
 >>> #CQL('Palomar assignment and "ice age"').dumps()
 
 >>> CQL('dinosaur not reptile').dumps()
-u'dinosaur not reptile'
+'dinosaur not reptile'
 
 >>> CQL('dinosaur and bird or dinobird').dumps()
-u'dinosaur and bird or dinobird'
+'dinosaur and bird or dinobird'
 
 >>> CQL('(bird or dinosaur) and (feathers or scales)').dumps()
-u'(bird or dinosaur) and (feathers or scales)'
+'(bird or dinosaur) and (feathers or scales)'
 
 >>> CQL('"feathered dinosaur" and (yixian or jehol)').dumps()
-u'"feathered dinosaur" and (yixian or jehol)'
+'"feathered dinosaur" and (yixian or jehol)'
 
 
 Queries accessing publication indexes
 =====================================
 
 >>> CQL('publicationYear < 1980').dumps()
-u'publicationYear < 1980'
+'publicationYear < 1980'
 
 >>> CQL('lengthOfFemur > 2.4').dumps()
-u'lengthOfFemur > 2.4'
+'lengthOfFemur > 2.4'
 
 >>> CQL('bioMass >= 100').dumps()
-u'bioMass >= 100'
+'bioMass >= 100'
 
 
 Queries based on the proximity of words to each other in a document
@@ -82,17 +82,17 @@ Queries across multiple dimensions
 ==================================
 
 >>> CQL('date within "2002 2005"').dumps()
-u'date within "2002 2005"'
+'date within "2002 2005"'
 
 >>> CQL('dateRange encloses 2003').dumps()
-u'dateRange encloses 2003'
+'dateRange encloses 2003'
 
 
 Queries based on relevance
 ==========================
 
 >>> CQL('subject any/relevant "fish frog"').dumps()
-u'subject any/relevant "fish frog"'
+'subject any/relevant "fish frog"'
 
 >>> CQL('subject any/rel.lr "fish frog"').dumps()
-u'subject any/rel.lr "fish frog"'
+'subject any/rel.lr "fish frog"'
diff --git a/patzilla/util/cql/pyparsing/test/05_misc.rst b/patzilla/util/cql/pyparsing/test/05_misc.rst
index ed175ba6..4ccdce8d 100644
--- a/patzilla/util/cql/pyparsing/test/05_misc.rst
+++ b/patzilla/util/cql/pyparsing/test/05_misc.rst
@@ -15,14 +15,14 @@ Queries with UTF-8 characters
 
 Try parsing a query containing utf-8 characters.
 
->>> CQL(u'title=molécules').dumps()
-u'title=mol\xe9cules'
+>>> CQL('title=molécules').dumps()
+'title=mol\xe9cules'
 
->>> CQL(u'inventor="CEGARRA SERRANO JOSÉ MARIANO"').dumps()
-u'inventor="CEGARRA SERRANO JOS\xc9 MARIANO"'
+>>> CQL('inventor="CEGARRA SERRANO JOSÉ MARIANO"').dumps()
+'inventor="CEGARRA SERRANO JOS\xc9 MARIANO"'
 
->>> CQL(u'ab=radaufstandskraft or ab=radaufstandskräfte?').dumps()
-u'ab=radaufstandskraft or ab=radaufstandskr\xe4fte?'
+>>> CQL('ab=radaufstandskraft or ab=radaufstandskräfte?').dumps()
+'ab=radaufstandskraft or ab=radaufstandskr\xe4fte?'
 
 # TODO: use more esoteric utf-8 characters, e.g. special chars et al.
 
@@ -30,7 +30,7 @@ Queries using wildcards
 =======================
 
 >>> CQL('txt=footw or txt=footw? or txt=footw# or txt=footw! and txt=footw*re').dumps()
-u'txt=footw or txt=footw? or txt=footw# or txt=footw! and txt=footw*re'
+'txt=footw or txt=footw? or txt=footw# or txt=footw! and txt=footw*re'
 
 
 Query with comments
@@ -41,16 +41,16 @@ Query with comments
 ...        (baz or qux))   -- comment 2
 ...
 ...    """).dumps()
-u'foo=(bar and (baz or qux))'
+'foo=(bar and (baz or qux))'
 
 
 Weird queries
 =============
 >>> CQL('   foobar   ').dumps()
-u'foobar'
+'foobar'
 
 >>> CQL('(((foobar)))').dumps()
-u'(((foobar)))'
+'(((foobar)))'
 
 
 Queries with errors
@@ -61,14 +61,14 @@ Nonsense
 >>> CQL('foo bar', logging=False).dumps()
 Traceback (most recent call last):
     ...
-ParseException: Expected end of text (at char 4), (line:1, col:5)
+ParseException: Expected end of text, found 'bar'  (at char 4), (line:1, col:5)
 
 Lacking terms
 -------------
 >>> CQL('foo=', logging=False).dumps()
 Traceback (most recent call last):
     ...
-ParseException: Expected term (at char 4), (line:1, col:5)
+ParseException: Expected end of text, found 'bar'  (at char 9), (line:1, col:10)
 
 >>> CQL('foo= and bar=', logging=False).dumps()
 Traceback (most recent call last):
@@ -92,12 +92,12 @@ Unknown binops
 >>> CQL('foo % bar', logging=False).dumps()
 Traceback (most recent call last):
     ...
-ParseException: Expected end of text (at char 4), (line:1, col:5)
+ParseException: Expected end of text, found 'bar'  (at char 4), (line:1, col:5)
 
 Error explanation
 -----------------
 >>> try:
-...     CQL(u'foo bar', logging=False).dumps()
+...     CQL('foo bar', logging=False).dumps()
 ... except Exception as ex:
 ...     ex.explanation
-u'foo bar\n    ^\n\nExpected end of text (at char 4), (line:1, col:5)'
+"foo bar\n    ^\n\nExpected end of text, found 'bar'  (at char 4), (line:1, col:5)"
diff --git a/patzilla/util/cql/pyparsing/test/10_extensions.rst b/patzilla/util/cql/pyparsing/test/10_extensions.rst
index 73c72e1e..02d217bc 100644
--- a/patzilla/util/cql/pyparsing/test/10_extensions.rst
+++ b/patzilla/util/cql/pyparsing/test/10_extensions.rst
@@ -18,13 +18,13 @@ Patent number normalization
 First, check parsing and reproducing a query for a publication number without normalization applied:
 
 >>> CQL('pn=EP666666').dumps()
-u'pn=EP666666'
+'pn=EP666666'
 
 
 Then, check whether normalization works correctly. Here, the EP document number should get zero-padded properly:
 
 >>> CQL('pn=EP666666').normalize_numbers().dumps()
-u'pn=EP0666666'
+'pn=EP0666666'
 
 
 Keyword extraction
@@ -33,13 +33,13 @@ Keyword extraction
 First, make sure the query can actually be parsed:
 
 >>> CQL('bi=greifer and pc=de').dumps()
-u'bi=greifer and pc=de'
+'bi=greifer and pc=de'
 
 
 Then, check the list of extracted keywords:
 
 >>> CQL('bi=greifer and pc=de').keywords()
-[u'greifer']
+['greifer']
 
 
 Details
@@ -53,8 +53,8 @@ because index name "pc" is not whitelisted.
 We can have a look at the layer below, where raw triples got extracted from the query string,
 that's the step just before collecting the keywords:
 
->>> CQL(u'bi=greifer and pc=de').triples()
-[[u'bi', u'=', u'greifer'], [u'pc', u'=', u'de']]
+>>> CQL('bi=greifer and pc=de').triples()
+[['bi', '=', 'greifer'], ['pc', '=', 'de']]
 
 This shows we also have access to the "pc=de" condition if
 there's demand for enhanced query analytics in the future.
@@ -70,13 +70,13 @@ Parse and reproduce a cql query containing a nested expression in value shortcut
 Our old token-based parser wasn't capable doing this.
 
 >>> CQL('bi=(socke and (Inlay or Teile)) and pc=de').dumps()
-u'bi=(socke and (Inlay or Teile)) and pc=de'
+'bi=(socke and (Inlay or Teile)) and pc=de'
 
 
 Expand the value shortcut notation:
 
 >>> CQL('bi=(socke and (Inlay or Teile)) and pc=de').expand_shortcuts().dumps()
-u'(bi=socke and (bi=Inlay or bi=Teile)) and pc=de'
+'(bi=socke and (bi=Inlay or bi=Teile)) and pc=de'
 
 
 Special operators
@@ -86,7 +86,7 @@ Boolean operators (binops) in german
 ------------------------------------
 
 >>> CQL('BI=Socke und PA=onion').dumps()
-u'BI=Socke UND PA=onion'
+'BI=Socke UND PA=onion'
 
 
 
@@ -108,7 +108,7 @@ Verbatim reproduction
 The query should be reproduced verbatim when not applying any expansion or normalization:
 
 >>> CQL(query).dumps()
-u'pn=(EP666666 or EP666667) or (cpc=H04L12/433 and txt=communication?)'
+'pn=(EP666666 or EP666667) or (cpc=H04L12/433 and txt=communication?)'
 
 
 Polishing
@@ -116,12 +116,12 @@ Polishing
 After shortcut expansion and number normalization, we should see zero-padded EP document numbers:
 
 >>> CQL(query).polish().dumps()
-u'(pn=EP0666666 or pn=EP0666667) or (cpc=H04L12/433 and txt=communication?)'
+'(pn=EP0666666 or pn=EP0666667) or (cpc=H04L12/433 and txt=communication?)'
 
 Terms from conditions for classification- or fulltext-indexes should count towards keywords:
 
 >>> CQL(query).polish().keywords()
-[u'H04L12/433', u'communication']
+['H04L12/433', 'communication']
 
 
 Details
@@ -130,13 +130,13 @@ Even without polishing the query, the keywords should be the same,
 since "cpc" and "txt" conditions both are not in value shortcut notation.
 
 >>> CQL(query).keywords()
-[u'H04L12/433', u'communication']
+['H04L12/433', 'communication']
 
 On the other hand, number normalization for numbers in value shortcut notation
 obviously does not work when not having shortcut expansion applied before:
 
 >>> CQL('pn=(EP666666 or EP666667)').normalize_numbers().dumps()
-u'pn=(EP666666 or EP666667)'
+'pn=(EP666666 or EP666667)'
 
 
 Nesting and keywords
@@ -146,4 +146,4 @@ We especially want to properly extract keywords from nested expressions,
 even when they are in value shortcut notation.
 
 >>> CQL('bi=(socke and (Inlay or Teile)) and pc=de').expand_shortcuts().keywords()
-[u'socke', u'Inlay', u'Teile']
+['socke', 'Inlay', 'Teile']
diff --git a/patzilla/util/cql/pyparsing/test/15_ops.rst b/patzilla/util/cql/pyparsing/test/15_ops.rst
index eae17e30..65d244f8 100644
--- a/patzilla/util/cql/pyparsing/test/15_ops.rst
+++ b/patzilla/util/cql/pyparsing/test/15_ops.rst
@@ -20,7 +20,7 @@ Date range
 Test date range condition used when extrapolating from vanity url, e.g. /publicationdate/2014W10.
 
 >>> CQL('publicationdate within 2014-03-10,2014-03-16').dumps()
-u'publicationdate within 2014-03-10,2014-03-16'
+'publicationdate within 2014-03-10,2014-03-16'
 
 
 Examples from OPS reference guide
@@ -37,23 +37,23 @@ CQL examples
 Original CQL examples from reference guide.
 
 >>> CQL('ti all "green, energy"').dumps()
-u'ti all "green, energy"'
+'ti all "green, energy"'
 
 .. note:: **FIXME: enhance grammar**
 
 >>> #CQL('ti=green prox/unit=world ti=energy').dumps()
 
 >>> CQL('pd within "20051212 20051214"').dumps()
-u'pd within "20051212 20051214"'
+'pd within "20051212 20051214"'
 
 >>> CQL('pd="20051212 20051214"').dumps()
-u'pd="20051212 20051214"'
+'pd="20051212 20051214"'
 
 >>> CQL('ia any "John, Smith"').dumps()
-u'ia any "John, Smith"'
+'ia any "John, Smith"'
 
 >>> CQL('pn=EP and pr=GB').dumps()
-u'pn=EP and pr=GB'
+'pn=EP and pr=GB'
 
 .. note:: **FIXME: enhance grammar**
 
@@ -62,19 +62,19 @@ u'pn=EP and pr=GB'
 >>> #CQL('(ta=green prox/distance<=3 ta=energy) or (ta=renewable prox/distance<=3 ta=energy)').dumps()
 
 >>> CQL('pa all "central, intelligence, agency" and US').dumps()
-u'pa all "central, intelligence, agency" and US'
+'pa all "central, intelligence, agency" and US'
 
 >>> CQL('pa all "central, intelligence, agency" and US and pd>2000').dumps()
-u'pa all "central, intelligence, agency" and US and pd > 2000'
+'pa all "central, intelligence, agency" and US and pd > 2000'
 
 >>> CQL('pd < 18000101').dumps()
-u'pd < 18000101'
+'pd < 18000101'
 
 >>> CQL('ta=synchroni#ed').dumps()
-u'ta=synchroni#ed'
+'ta=synchroni#ed'
 
 >>> CQL('EP and 2009 and Smith').dumps()
-u'EP and 2009 and Smith'
+'EP and 2009 and Smith'
 
 
 .. note:: **FIXME: enhance grammar**
@@ -91,23 +91,23 @@ Shortcut notation expansion
 All these should not be affected by any query manipulation. Prove that.
 
 >>> CQL('pa all "central, intelligence, agency" and US').polish().dumps()
-u'pa all "central, intelligence, agency" and US'
+'pa all "central, intelligence, agency" and US'
 
 >>> CQL('pa all "central, intelligence, agency" and US and pd>2000').polish().dumps()
-u'pa all "central, intelligence, agency" and US and pd > 2000'
+'pa all "central, intelligence, agency" and US and pd > 2000'
 
 >>> CQL('EP and 2009 and Smith').polish().dumps()
-u'EP and 2009 and Smith'
+'EP and 2009 and Smith'
 
 
 Keyword extraction
 ------------------
 
 >>> CQL('pa all "central, intelligence, agency" and US').polish().keywords()
-[u'central', u'intelligence', u'agency']
+['central', 'intelligence', 'agency']
 
 >>> CQL('pa all "central intelligence agency" and US').polish().keywords()
-[u'central', u'intelligence', u'agency']
+['central', 'intelligence', 'agency']
 
 .. note:: **FIXME: enhance parser smartness: follow rules outlined on p. 148, section 4.2. CQL index catalogue**
 
diff --git a/patzilla/util/cql/pyparsing/test/20_depatisnet.rst b/patzilla/util/cql/pyparsing/test/20_depatisnet.rst
index 3f22af00..176137dd 100644
--- a/patzilla/util/cql/pyparsing/test/20_depatisnet.rst
+++ b/patzilla/util/cql/pyparsing/test/20_depatisnet.rst
@@ -27,19 +27,19 @@ Test some logic operators localized to german.
 Getting started
 ---------------
 >>> CQL('bi=(greifer oder bagger)').dumps()
-u'bi=(greifer ODER bagger)'
+'bi=(greifer ODER bagger)'
 
 Made up
 -------
 Try to understand the query.
 
->>> CQL(u'bi=((wasser UND Getränk) NICHT (?hahn oder ?zapf oder (kühl? oder ?kühl)))').dumps()
-u'bi=((wasser UND Getr\xe4nk) NICHT (?hahn ODER ?zapf ODER (k\xfchl? ODER ?k\xfchl)))'
+>>> CQL('bi=((wasser UND Getränk) NICHT (?hahn oder ?zapf oder (kühl? oder ?kühl)))').dumps()
+'bi=((wasser UND Getr\xe4nk) NICHT (?hahn ODER ?zapf ODER (k\xfchl? ODER ?k\xfchl)))'
 
 Extract keywords from query.
 
->>> CQL(u'bi=((wasser UND Getränk) NICHT (?hahn oder ?zapf oder (kühl? oder ?kühl)))').polish().keywords()
-[u'wasser', u'Getr\xe4nk', u'hahn', u'zapf', u'k\xfchl', u'k\xfchl']
+>>> CQL('bi=((wasser UND Getränk) NICHT (?hahn oder ?zapf oder (kühl? oder ?kühl)))').polish().keywords()
+['wasser', 'Getr\xe4nk', 'hahn', 'zapf', 'k\xfchl', 'k\xfchl']
 
 
 Neighbourhood operators
@@ -50,18 +50,18 @@ Getting started
 
 Try a bareword query string containing a neighbourhood term operator:
 
->>> CQL(u'L(W)Serine').dumps()
-u'L(W)Serine'
+>>> CQL('L(W)Serine').dumps()
+'L(W)Serine'
 
 Try the same in the context of a real condition (triple):
 
->>> CQL(u'ab=(L(W)Serine)').dumps()
-u'ab=(L(W)Serine)'
+>>> CQL('ab=(L(W)Serine)').dumps()
+'ab=(L(W)Serine)'
 
 Check this works caseless as well:
 
->>> CQL(u'L(w)Serine').dumps()
-u'L(W)Serine'
+>>> CQL('L(w)Serine').dumps()
+'L(W)Serine'
 
 
 Made up
@@ -69,14 +69,14 @@ Made up
 
 Try some more complex queries containing neighbourhood term operators and wildcards.
 
->>> CQL(u'bi=(Cry1?(L)resist?)').dumps()
-u'bi=(Cry1?(L)resist?)'
+>>> CQL('bi=(Cry1?(L)resist?)').dumps()
+'bi=(Cry1?(L)resist?)'
 
->>> CQL(u'bi=(Cry1?(5A)tox?)').dumps()
-u'bi=(Cry1?(5A)tox?)'
+>>> CQL('bi=(Cry1?(5A)tox?)').dumps()
+'bi=(Cry1?(5A)tox?)'
 
->>> CQL(u'bi=(Misch?(P)?wasser)').dumps()
-u'bi=(Misch?(P)?wasser)'
+>>> CQL('bi=(Misch?(P)?wasser)').dumps()
+'bi=(Misch?(P)?wasser)'
 
 
 
@@ -93,91 +93,91 @@ Search examples
 ---------------
 
 >>> CQL('PA= siemens').dumps()
-u'PA=siemens'
+'PA=siemens'
 
 >>> CQL('PUB= 01.03.2010 UND PA= siemens').dumps()
-u'PUB=01.03.2010 UND PA=siemens'
+'PUB=01.03.2010 UND PA=siemens'
 
 >>> CQL('PA= siemens UND IN= Braun UND PUB>= 01.03.2010').dumps()
-u'PA=siemens UND IN=Braun UND PUB >= 01.03.2010'
+'PA=siemens UND IN=Braun UND PUB >= 01.03.2010'
 
 >>> CQL('PUB= M11-2009 UND PA= daimler?').dumps()
-u'PUB=M11-2009 UND PA=daimler?'
+'PUB=M11-2009 UND PA=daimler?'
 
->>> CQL(u'AB = !!!lösung').dumps()
-u'AB=!!!l\xf6sung'
+>>> CQL('AB = !!!lösung').dumps()
+'AB=!!!l\xf6sung'
 
 >>> CQL('TI = ###heizung').dumps()
-u'TI=###heizung'
+'TI=###heizung'
 
 >>> CQL('CL = ?fahrzeug').dumps()
-u'CL=?fahrzeug'
+'CL=?fahrzeug'
 
 >>> CQL('BI= (programmabschnitt# UND administra?)').dumps()
-u'BI=(programmabschnitt# UND administra?)'
+'BI=(programmabschnitt# UND administra?)'
 
 
 >>> CQL('ICB=F17D5/00').dumps()
-u'ICB=F17D5/00'
+'ICB=F17D5/00'
 
 >>> CQL('ICB=F17D5-00').dumps()
-u'ICB=F17D5-00'
+'ICB=F17D5-00'
 
 >>> CQL("ICB='F17D 5/00'").dumps()
-u"ICB='F17D 5/00'"
+"ICB='F17D 5/00'"
 
 >>> CQL('ICB=F17D0005000000').dumps()
-u'ICB=F17D0005000000'
+'ICB=F17D0005000000'
 
 
 >>> CQL('ICP=F17D5/00M').dumps()
-u'ICP=F17D5/00M'
+'ICP=F17D5/00M'
 
 >>> CQL('ICP=F17D5-00M').dumps()
-u'ICP=F17D5-00M'
+'ICP=F17D5-00M'
 
 >>> CQL("ICP='F17D 5/00 M'").dumps()
-u"ICP='F17D 5/00 M'"
+"ICP='F17D 5/00 M'"
 
 >>> CQL('ICP=F17D000500000M').dumps()
-u'ICP=F17D000500000M'
+'ICP=F17D000500000M'
 
 
 >>> CQL('ICB=F04D13/?').dumps()
-u'ICB=F04D13/?'
+'ICB=F04D13/?'
 
 >>> CQL('ICB=F04D13-?').dumps()
-u'ICB=F04D13-?'
+'ICB=F04D13-?'
 
 >>> CQL("ICB='F04D 13/?'").dumps()
-u"ICB='F04D 13/?'"
+"ICB='F04D 13/?'"
 
 >>> CQL('ICB=F04D0013?').dumps()
-u'ICB=F04D0013?'
+'ICB=F04D0013?'
 
 
 Search examples for the proximity operator (NOTW)
 -------------------------------------------------
 >>> CQL('Bi= (Regler und (mechanische(NOTW)Regler))').dumps()
-u'Bi=(Regler UND (mechanische(NOTW)Regler))'
+'Bi=(Regler UND (mechanische(NOTW)Regler))'
 
 >>> CQL('Bi= (Regler und (mechanische (NOTW) Regler))').dumps()
-u'Bi=(Regler UND (mechanische (NOTW) Regler))'
+'Bi=(Regler UND (mechanische (NOTW) Regler))'
 
 
 Searches in the text fields "Title", "Abstract", "Description", "Claims", "Full text data"
 ------------------------------------------------------------------------------------------
 >>> CQL('TI = ( DVB(W)T )').dumps()
-u'TI=(DVB(W)T)'
+'TI=(DVB(W)T)'
 
 >>> CQL('Bi= (personalcomputer oder (personal(W)computer))').dumps()
-u'Bi=(personalcomputer ODER (personal(W)computer))'
+'Bi=(personalcomputer ODER (personal(W)computer))'
 
 
 Searches in the fields "Applicant/owner", "Inventor"
 ----------------------------------------------------
 >>> CQL('PA = ( Anna(L)Huber )').dumps()
-u'PA=(Anna(L)Huber)'
+'PA=(Anna(L)Huber)'
 
 
 Keywords
@@ -185,7 +185,7 @@ Keywords
 
 Try some more complex queries containing *value shortcut notations*, *neighbourhood term operators* and *wildcards*.
 
->>> largequery = u"""
+>>> largequery = """
 ...     (PA= siemens UND IN= Braun UND PUB>= 01.03.2010) or
 ...     (PUB=M11-2009 UND PA=daimler?) or
 ...     (AB = (!!!lösung or ###heizung or ?fahrzeug)) or
@@ -195,10 +195,10 @@ Try some more complex queries containing *value shortcut notations*, *neighbourh
 ... """
 
 >>> CQL(largequery).dumps()
-u"(PA=siemens UND IN=Braun UND PUB >= 01.03.2010) or (PUB=M11-2009 UND PA=daimler?) or (AB=(!!!l\xf6sung or ###heizung or ?fahrzeug)) or (ICB='F17D 5/00' or ICB=F04D13-?) or bi=(mechanische (NOTW) Regler) or bi=(Cry1?(L)resist? or Cry1?(5A)tox? or Misch?(P)?wasser)"
+"(PA=siemens UND IN=Braun UND PUB >= 01.03.2010) or (PUB=M11-2009 UND PA=daimler?) or (AB=(!!!l\xf6sung or ###heizung or ?fahrzeug)) or (ICB='F17D 5/00' or ICB=F04D13-?) or bi=(mechanische (NOTW) Regler) or bi=(Cry1?(L)resist? or Cry1?(5A)tox? or Misch?(P)?wasser)"
 
 >>> CQL(largequery).keywords()
-[u'siemens', u'Braun', u'daimler', u'F17D 5/00', u'F04D13-', [u'mechanische', u'Regler']]
+['siemens', 'Braun', 'daimler', 'F17D 5/00', 'F04D13-', ['mechanische', 'Regler']]
 
 
 Polishing
@@ -207,20 +207,20 @@ Polishing
 Polishing a query, especially the shortcut notation expansion, should not corrupt query syntax.
 
 >>> CQL('TI = ( DVB(W)T )').polish().dumps()
-u'TI=(DVB(W)T)'
+'TI=(DVB(W)T)'
 
 >>> CQL('Bi= (personalcomputer oder (personal(W)computer))').polish().dumps()
-u'(Bi=personalcomputer ODER (Bi=(personal(W)computer)))'
+'(Bi=personalcomputer ODER (Bi=(personal(W)computer)))'
 
 >>> CQL('bi=(Cry1?(L)resist?)').polish().dumps()
-u'bi=(Cry1?(L)resist?)'
+'bi=(Cry1?(L)resist?)'
 
 
 >>> CQL(largequery).polish().dumps()
-u"(PA=siemens UND IN=Braun UND PUB >= 01.03.2010) or (PUB=M11-2009 UND PA=daimler?) or ((AB=!!!l\xf6sung or AB=###heizung or AB=?fahrzeug)) or (ICB='F17D 5/00' or ICB=F04D13-?) or bi=(mechanische (NOTW) Regler) or (bi=(Cry1?(L)resist?) or bi=(Cry1?(5A)tox?) or bi=(Misch?(P)?wasser))"
+"(PA=siemens UND IN=Braun UND PUB >= 01.03.2010) or (PUB=M11-2009 UND PA=daimler?) or ((AB=!!!l\xf6sung or AB=###heizung or AB=?fahrzeug)) or (ICB='F17D 5/00' or ICB=F04D13-?) or bi=(mechanische (NOTW) Regler) or (bi=(Cry1?(L)resist?) or bi=(Cry1?(5A)tox?) or bi=(Misch?(P)?wasser))"
 
 >>> CQL(largequery).polish().keywords()
-[u'siemens', u'Braun', u'daimler', u'l\xf6sung', u'heizung', u'fahrzeug', u'F17D 5/00', u'F04D13-', [u'mechanische', u'Regler'], [u'Cry1', u'resist'], [u'Cry1', u'tox'], [u'Misch', u'wasser']]
+['siemens', 'Braun', 'daimler', 'l\xf6sung', 'heizung', 'fahrzeug', 'F17D 5/00', 'F04D13-', ['mechanische', 'Regler'], ['Cry1', 'resist'], ['Cry1', 'tox'], ['Misch', 'wasser']]
 
 
 From the wild
@@ -233,18 +233,18 @@ Query 1
 
 Reproduce verbatim:
 
->>> print(CQL(u'(ab=radaufstandskraft or ab=radaufstandskräfte?)').dumps())
+>>> print(CQL('(ab=radaufstandskraft or ab=radaufstandskräfte?)').dumps())
 (ab=radaufstandskraft or ab=radaufstandskräfte?)
 
 Reproduce with polishing:
 
->>> print(CQL(u'(ab=radaufstandskraft or ab=radaufstandskräfte?)').polish().dumps())
+>>> print(CQL('(ab=radaufstandskraft or ab=radaufstandskräfte?)').polish().dumps())
 (ab=radaufstandskraft or ab=radaufstandskräfte?)
 
 Extract keywords after polishing:
 
->>> CQL(u'(ab=radaufstandskraft or ab=radaufstandskräfte?)').polish().keywords()
-[u'radaufstandskraft', u'radaufstandskr\xe4fte']
+>>> CQL('(ab=radaufstandskraft or ab=radaufstandskräfte?)').polish().keywords()
+['radaufstandskraft', 'radaufstandskr\xe4fte']
 
 
 Query 2
@@ -252,18 +252,18 @@ Query 2
 
 Reproduce verbatim:
 
->>> print(CQL(u'bi=( ( warm(P)walzen)  AND ( band(P)mitte and messung) )  oder  bi=( ( warm  and walzen)  AND ( band and säbel and messung) ) oder bi=((warm and walzen)and (mitten und messung)) oder  BI =((reversiergerüst)und(breitenmessung))').dumps())
+>>> print(CQL('bi=( ( warm(P)walzen)  AND ( band(P)mitte and messung) )  oder  bi=( ( warm  and walzen)  AND ( band and säbel and messung) ) oder bi=((warm and walzen)and (mitten und messung)) oder  BI =((reversiergerüst)und(breitenmessung))').dumps())
 bi=((warm(P)walzen) and (band(P)mitte and messung)) ODER bi=((warm and walzen) and (band and säbel and messung)) ODER bi=((warm and walzen) and (mitten UND messung)) ODER BI=((reversiergerüst) UND (breitenmessung))
 
 Reproduce with polishing:
 
->>> print(CQL(u'bi=( ( warm(P)walzen)  AND ( band(P)mitte and messung) )  oder  bi=( ( warm  and walzen)  AND ( band and säbel and messung) ) oder bi=((warm and walzen)and (mitten und messung)) oder  BI =((reversiergerüst)und(breitenmessung))').polish().dumps())
+>>> print(CQL('bi=( ( warm(P)walzen)  AND ( band(P)mitte and messung) )  oder  bi=( ( warm  and walzen)  AND ( band and säbel and messung) ) oder bi=((warm and walzen)and (mitten und messung)) oder  BI =((reversiergerüst)und(breitenmessung))').polish().dumps())
 ((bi=(warm(P)walzen)) and (bi=(band(P)mitte) and bi=messung)) ODER ((bi=warm and bi=walzen) and (bi=band and bi=säbel and bi=messung)) ODER ((bi=warm and bi=walzen) and (bi=mitten UND bi=messung)) ODER ((BI=reversiergerüst) UND (BI=breitenmessung))
 
 Extract keywords after polishing:
 
->>> CQL(u'bi=( ( warm(P)walzen)  AND ( band(P)mitte and messung) )  oder  bi=( ( warm  and walzen)  AND ( band and säbel and messung) ) oder bi=((warm and walzen)and (mitten und messung)) oder  BI =((reversiergerüst)und(breitenmessung))').polish().keywords()
-[[u'warm', u'walzen'], [u'band', u'mitte'], u'messung', u'warm', u'walzen', u'band', u's\xe4bel', u'messung', u'warm', u'walzen', u'mitten', u'messung', u'reversierger\xfcst', u'breitenmessung']
+>>> CQL('bi=( ( warm(P)walzen)  AND ( band(P)mitte and messung) )  oder  bi=( ( warm  and walzen)  AND ( band and säbel and messung) ) oder bi=((warm and walzen)and (mitten und messung)) oder  BI =((reversiergerüst)und(breitenmessung))').polish().keywords()
+[['warm', 'walzen'], ['band', 'mitte'], 'messung', 'warm', 'walzen', 'band', 's\xe4bel', 'messung', 'warm', 'walzen', 'mitten', 'messung', 'reversierger\xfcst', 'breitenmessung']
 
 
 Query 3
@@ -271,18 +271,18 @@ Query 3
 
 Reproduce verbatim:
 
->>> print(CQL(u'bi=( ( hot(P)rolling)  AND ( strip(P)center and measurement)  oder ( hot  and rolling)  AND ( strip and camber and measurement) ) oder bi=((reversing and mill)and (camber)) ODER bi=( ( hot  and steel)  AND (center and measurement) )  ODER BI =((hot(P)slab) und(position(P)measurement)) ODER BI =((hot(P)strip) und(position(P)measurement))').dumps())
+>>> print(CQL('bi=( ( hot(P)rolling)  AND ( strip(P)center and measurement)  oder ( hot  and rolling)  AND ( strip and camber and measurement) ) oder bi=((reversing and mill)and (camber)) ODER bi=( ( hot  and steel)  AND (center and measurement) )  ODER BI =((hot(P)slab) und(position(P)measurement)) ODER BI =((hot(P)strip) und(position(P)measurement))').dumps())
 bi=((hot(P)rolling) and (strip(P)center and measurement) ODER (hot and rolling) and (strip and camber and measurement)) ODER bi=((reversing and mill) and (camber)) ODER bi=((hot and steel) and (center and measurement)) ODER BI=((hot(P)slab) UND (position(P)measurement)) ODER BI=((hot(P)strip) UND (position(P)measurement))
 
 Reproduce with polishing:
 
->>> print(CQL(u'bi=( ( hot(P)rolling)  AND ( strip(P)center and measurement)  oder ( hot  and rolling)  AND ( strip and camber and measurement) ) oder bi=((reversing and mill)and (camber)) ODER bi=( ( hot  and steel)  AND (center and measurement) )  ODER BI =((hot(P)slab) und(position(P)measurement)) ODER BI =((hot(P)strip) und(position(P)measurement))').polish().dumps())
+>>> print(CQL('bi=( ( hot(P)rolling)  AND ( strip(P)center and measurement)  oder ( hot  and rolling)  AND ( strip and camber and measurement) ) oder bi=((reversing and mill)and (camber)) ODER bi=( ( hot  and steel)  AND (center and measurement) )  ODER BI =((hot(P)slab) und(position(P)measurement)) ODER BI =((hot(P)strip) und(position(P)measurement))').polish().dumps())
 ((bi=(hot(P)rolling)) and (bi=(strip(P)center) and bi=measurement) ODER (bi=hot and bi=rolling) and (bi=strip and bi=camber and bi=measurement)) ODER ((bi=reversing and bi=mill) and (bi=camber)) ODER ((bi=hot and bi=steel) and (bi=center and bi=measurement)) ODER ((BI=(hot(P)slab)) UND (BI=(position(P)measurement))) ODER ((BI=(hot(P)strip)) UND (BI=(position(P)measurement)))
 
 Extract keywords after polishing:
 
->>> CQL(u'bi=( ( hot(P)rolling)  AND ( strip(P)center and measurement)  oder ( hot  and rolling)  AND ( strip and camber and measurement) ) oder bi=((reversing and mill)and (camber)) ODER bi=( ( hot  and steel)  AND (center and measurement) )  ODER BI =((hot(P)slab) und(position(P)measurement)) ODER BI =((hot(P)strip) und(position(P)measurement))').polish().keywords()
-[[u'hot', u'rolling'], [u'strip', u'center'], u'measurement', u'hot', u'rolling', u'strip', u'camber', u'measurement', u'reversing', u'mill', u'camber', u'hot', u'steel', u'center', u'measurement', [u'hot', u'slab'], [u'position', u'measurement'], [u'hot', u'strip'], [u'position', u'measurement']]
+>>> CQL('bi=( ( hot(P)rolling)  AND ( strip(P)center and measurement)  oder ( hot  and rolling)  AND ( strip and camber and measurement) ) oder bi=((reversing and mill)and (camber)) ODER bi=( ( hot  and steel)  AND (center and measurement) )  ODER BI =((hot(P)slab) und(position(P)measurement)) ODER BI =((hot(P)strip) und(position(P)measurement))').polish().keywords()
+[['hot', 'rolling'], ['strip', 'center'], 'measurement', 'hot', 'rolling', 'strip', 'camber', 'measurement', 'reversing', 'mill', 'camber', 'hot', 'steel', 'center', 'measurement', ['hot', 'slab'], ['position', 'measurement'], ['hot', 'strip'], ['position', 'measurement']]
 
 
 Query 4
@@ -290,15 +290,15 @@ Query 4
 
 Reproduce verbatim:
 
->>> print(CQL(u'BI=((finne? or (flying(1a)buttress?) or fins or effillee?) and (viergelenk? or mehrgelenk? or quadrilateral? or quadruple? or (four(w)joint) or quadrilaterale or quatre))').dumps())
+>>> print(CQL('BI=((finne? or (flying(1a)buttress?) or fins or effillee?) and (viergelenk? or mehrgelenk? or quadrilateral? or quadruple? or (four(w)joint) or quadrilaterale or quatre))').dumps())
 BI=((finne? or (flying(1A)buttress?) or fins or effillee?) and (viergelenk? or mehrgelenk? or quadrilateral? or quadruple? or (four(W)joint) or quadrilaterale or quatre))
 
 Reproduce with polishing:
 
->>> print(CQL(u'BI=((finne? or (flying(1a)buttress?) or fins or effillee?) and (viergelenk? or mehrgelenk? or quadrilateral? or quadruple? or (four(w)joint) or quadrilaterale or quatre))').polish().dumps())
+>>> print(CQL('BI=((finne? or (flying(1a)buttress?) or fins or effillee?) and (viergelenk? or mehrgelenk? or quadrilateral? or quadruple? or (four(w)joint) or quadrilaterale or quatre))').polish().dumps())
 ((BI=finne? or (BI=(flying(1A)buttress?)) or BI=fins or BI=effillee?) and (BI=viergelenk? or BI=mehrgelenk? or BI=quadrilateral? or BI=quadruple? or (BI=(four(W)joint)) or BI=quadrilaterale or BI=quatre))
 
 Extract keywords after polishing:
 
->>> CQL(u'BI=((finne? or (flying(1a)buttress?) or fins or effillee?) and (viergelenk? or mehrgelenk? or quadrilateral? or quadruple? or (four(w)joint) or quadrilaterale or quatre))').polish().keywords()
-[u'finne', [u'flying', u'buttress'], u'fins', u'effillee', u'viergelenk', u'mehrgelenk', u'quadrilateral', u'quadruple', [u'four', u'joint'], u'quadrilaterale', u'quatre']
+>>> CQL('BI=((finne? or (flying(1a)buttress?) or fins or effillee?) and (viergelenk? or mehrgelenk? or quadrilateral? or quadruple? or (four(w)joint) or quadrilaterale or quatre))').polish().keywords()
+['finne', ['flying', 'buttress'], 'fins', 'effillee', 'viergelenk', 'mehrgelenk', 'quadrilateral', 'quadruple', ['four', 'joint'], 'quadrilaterale', 'quatre']
diff --git a/patzilla/util/cql/pyparsing/test/30_ificlaims.rst b/patzilla/util/cql/pyparsing/test/30_ificlaims.rst
index 3659f21e..0385cfc7 100644
--- a/patzilla/util/cql/pyparsing/test/30_ificlaims.rst
+++ b/patzilla/util/cql/pyparsing/test/30_ificlaims.rst
@@ -29,16 +29,16 @@ Test some logic operators localized to german.
 Getting started
 ---------------
 >>> CQL('pnctry:EP AND text:vibrat*').dumps()
-u'pnctry : EP and text : vibrat*'
+'pnctry : EP and text : vibrat*'
 
 Made up
 -------
 Try to understand the query.
 
->>> CQL(u'(pnctry:EP and (pnctry:EP AND text:vibrat* AND (ic:G01F000184 OR cpc:G01F000184)))').dumps()
-u'(pnctry : EP and (pnctry : EP and text : vibrat* and (ic : G01F000184 or cpc : G01F000184)))'
+>>> CQL('(pnctry:EP and (pnctry:EP AND text:vibrat* AND (ic:G01F000184 OR cpc:G01F000184)))').dumps()
+'(pnctry : EP and (pnctry : EP and text : vibrat* and (ic : G01F000184 or cpc : G01F000184)))'
 
 Extract keywords from query.
 
->>> CQL(u'(pnctry:EP and (pnctry:EP AND text:vibrat* AND (ic:G01F000184 OR cpc:G01F000184)))').polish().keywords()
-[u'vibrat', u'G01F000184', u'G01F000184']
+>>> CQL('(pnctry:EP and (pnctry:EP AND text:vibrat* AND (ic:G01F000184 OR cpc:G01F000184)))').polish().keywords()
+['vibrat', 'G01F000184', 'G01F000184']
diff --git a/patzilla/util/cql/pyparsing/util.py b/patzilla/util/cql/pyparsing/util.py
index a202a99b..199a804c 100644
--- a/patzilla/util/cql/pyparsing/util.py
+++ b/patzilla/util/cql/pyparsing/util.py
@@ -2,14 +2,6 @@
 # (c) 2014-2016 Andreas Motl, Elmyra UG
 from pyparsing import ParseResults
 
-def get_literals(*elements):
-    literals = []
-    for element in elements:
-        for literal in element:
-            literal = unicode(literal).strip('"').strip("'")
-            literals.append(literal)
-    return literals
-
 def walk_token_results(tokens, *args, **kwargs):
 
     for token in tokens:
diff --git a/patzilla/util/cql/util.py b/patzilla/util/cql/util.py
index 07787f47..d117bf5f 100644
--- a/patzilla/util/cql/util.py
+++ b/patzilla/util/cql/util.py
@@ -15,7 +15,7 @@ def pair_to_cql(datasource, key, value):
         return
 
     cql_part = None
-    format = u'{0}=({1})'
+    format = '{0}=({1})'
 
     # Special processing rules for depatisnet
     if datasource == 'depatisnet':
@@ -94,7 +94,7 @@ def pair_to_cql(datasource, key, value):
 
         if key == 'inventor' or key == 'applicant':
             if not has_booleans(value) and should_be_quoted(value):
-                value = u'"{0}"'.format(value)
+                value = '"{0}"'.format(value)
 
         if key == 'pubdate':
 
diff --git a/patzilla/util/crypto/jwt.py b/patzilla/util/crypto/jwt.py
index 204727ba..194728f4 100644
--- a/patzilla/util/crypto/jwt.py
+++ b/patzilla/util/crypto/jwt.py
@@ -1,13 +1,15 @@
 # -*- coding: utf-8 -*-
-# (c) 2014-2022 Andreas Motl <andreas.motl@ip-tools.org>
-from __future__ import absolute_import
+
+# (c) 2014 Andreas Motl, Elmyra UG
+
 import logging
 from datetime import datetime, timedelta
 
 import python_jwt
 from jwcrypto import jwk
 from zope.interface.interface import Interface
-from zope.interface.declarations import implements
+#from zope.interface.declarations import implements
+from zope.interface import implementer
 
 log = logging.getLogger(__name__)
 
@@ -16,6 +18,7 @@ class ISigner(Interface):
     pass
 
 
+@implementer(ISigner)
 class JwtSigner(object):
     """
     Generate and verify JSON Web Tokens.
@@ -26,7 +29,7 @@ class JwtSigner(object):
     - https://jwcrypto.readthedocs.io/
     """
 
-    implements(ISigner)
+# py27  implements(ISigner)
 
     def __init__(self, key=None, ttl=None):
         self.key = key
@@ -86,7 +89,7 @@ def unsign(self, token):
                 iat_skew=timedelta(minutes=5),
             )
 
-            if not payload.has_key('data'):
+            if 'data' not in payload:
                 error_payload = {
                     'location': 'JSON Web Token',
                     'name': self.__class__.__name__,
diff --git a/patzilla/util/data/container.py b/patzilla/util/data/container.py
index d9c06532..22b3b05e 100644
--- a/patzilla/util/data/container.py
+++ b/patzilla/util/data/container.py
@@ -2,11 +2,11 @@
 # (c) 2016 Andreas Motl, Elmyra UG
 import json
 import types
-from bunch import Bunch
+from munch import Munch
 from jsonpointer import JsonPointer
 
 
-class SmartBunch(Bunch):
+class SmartMunch(Munch):
 
     def dump(self):
         return self.toJSON()
@@ -18,15 +18,15 @@ def prettify(self):
         return self.pretty()
 
     @classmethod
-    def bunchify(cls, x):
+    def munchify(cls, x):
         """
-        Recursively transforms a dictionary into a SmartBunch via copy.
-        Generic "bunchify", also works with descendants of Bunch.
+        Recursively transforms a dictionary into a SmartMunch via copy.
+        Generic "munchify", also works with descendants of Munch.
         """
         if isinstance(x, dict):
-            return cls( (k, cls.bunchify(v)) for k,v in x.iteritems() )
+            return cls( (k, cls.munchify(v)) for k,v in x.items() )
         elif isinstance(x, (list, tuple)):
-            return type(x)( cls.bunchify(v) for v in x )
+            return type(x)( cls.munchify(v) for v in x )
         else:
             return x
 
@@ -35,7 +35,7 @@ def unique_sequence(seq):
     # https://stackoverflow.com/questions/480214/how-do-you-remove-duplicates-from-a-list-in-python-whilst-preserving-order/480227#480227
     seen = set()
     seen_add = seen.add
-    unhashable_types = (types.ListType, types.DictionaryType)
+    unhashable_types = (list, dict)
     return [x for x in seq if type(x) in unhashable_types or not (x in seen or seen_add(x))]
 
 
diff --git a/patzilla/util/data/orderedset.py b/patzilla/util/data/orderedset.py
index 5ba05be5..43e45da1 100644
--- a/patzilla/util/data/orderedset.py
+++ b/patzilla/util/data/orderedset.py
@@ -2,7 +2,7 @@
 # Set that remembers original insertion order.
 import collections
 
-class OrderedSet(collections.MutableSet):
+class OrderedSet(collections.abc.MutableSet):
 
     def __init__(self, iterable=None):
         self.end = end = []
@@ -64,6 +64,6 @@ def __eq__(self, other):
 if __name__ == '__main__':
     s = OrderedSet('abracadaba')
     t = OrderedSet('simsalabim')
-    print(s | t)
-    print(s & t)
-    print(s - t)
+    print((s | t))
+    print((s & t))
+    print((s - t))
diff --git a/patzilla/util/data/zip.py b/patzilla/util/data/zip.py
index 9c9b472b..9879aa9c 100644
--- a/patzilla/util/data/zip.py
+++ b/patzilla/util/data/zip.py
@@ -17,7 +17,7 @@ def zip_multi(multi):
     now = time.localtime(time.time())[:6]
 
     # http://stackoverflow.com/questions/434641/how-do-i-set-permissions-attributes-on-a-file-in-a-zip-file-using-pythons-zip/434689#434689
-    unix_permissions = 0644 << 16L
+    unix_permissions = 0o644 << 16
 
     # add index file for drawings
     """
diff --git a/patzilla/util/database/beaker_mongodb.py b/patzilla/util/database/beaker_mongodb.py
index 4ccab80c..21938c99 100644
--- a/patzilla/util/database/beaker_mongodb.py
+++ b/patzilla/util/database/beaker_mongodb.py
@@ -184,235 +184,194 @@
 before upgrading to 0.5+ and be aware that it will generate new caches.
 
 
-
+A part of this code is a copy of https://raw.githubusercontent.com/bbangert/beaker/master/beaker/ext/mongodb.py 2023-03-22
 """
 
 
-import logging
-from beaker.container import NamespaceManager, Container
-from beaker.exceptions import InvalidCacheBackendError, MissingCacheParameter
-from beaker.synchronization import null_synchronizer
-from beaker.util import verify_directory, SyncDict
-
-from StringIO import StringIO
-try:
-    import cPickle as pickle
-except ImportError:
-    import pickle
+import datetime
+import os
+import threading
+import time
+import pickle
 
 try:
-    from pymongo.connection import Connection
+    import pymongo
+    import pymongo.errors
     import bson
-    import bson.errors
 except ImportError:
-    raise InvalidCacheBackendError("Unable to load the pymongo driver.")
-
-log = logging.getLogger(__name__)
-#log.setLevel(logging.DEBUG)
-
-class MongoDBNamespaceManager(NamespaceManager):
-    clients = SyncDict()
-    _pickle = True
-    _sparse = False
+    pymongo = None
+    bson = None
 
-    # TODO _- support write concern / safe
-    def __init__(self, namespace, url=None, data_dir=None, skip_pickle=False,
-                 sparse_collection=False, **params):
-        NamespaceManager.__init__(self, namespace)
+from beaker.container import NamespaceManager
+from beaker.synchronization import SynchronizerImpl
+from beaker.util import SyncDict, machine_identifier
+from beaker.crypto.util import sha1
+from beaker._compat import string_type, PY2
 
-        if not url:
-            raise MissingCacheParameter("MongoDB url is required")
 
-        if skip_pickle:
-            log.info("Disabling pickling for namespace: %s" % self.namespace)
-            self._pickle = False
+class MongoNamespaceManager(NamespaceManager):
+    """Provides the :class:`.NamespaceManager` API over MongoDB.
 
-        if sparse_collection:
-            log.info("Separating data to one row per key (sparse collection) for ns %s ." % self.namespace)
-            self._sparse = True
+    Provided ``url`` can be both a mongodb connection string or
+    an already existing MongoClient instance.
 
-        # Temporarily uses a local copy of the functions until pymongo upgrades to new parser code
-        (host_list, database, username, password, collection, options) = _parse_uri(url)
-
-        if database and host_list:
-            data_key = "mongodb:%s" % (database)
-        else:
-            raise MissingCacheParameter("Invalid Cache URL.  Cannot parse.")
-
-        def _create_mongo_conn():
-            host_uri = 'mongodb://'
-            for x in host_list:
-                host_uri += '%s:%s' % x
-            log.info("Host URI: %s" % host_uri)
-            conn = Connection(host_uri, slave_okay=options.get('slaveok', False))
+    The data will be stored into ``beaker_cache`` collection of the
+    *default database*, so make sure your connection string or
+    MongoClient point to a default database.
+    """
+    MAX_KEY_LENGTH = 1024
 
-            db = conn[database]
+    clients = SyncDict()
 
-            if username:
-                log.info("Attempting to authenticate %s/%s " % (username, password))
-                if not db.authenticate(username, password):
-                    raise InvalidCacheBackendError('Cannot authenticate to '
-                                                   ' MongoDB.')
-            return db[collection]
+    def __init__(self, namespace, url, **kw):
+        super(MongoNamespaceManager, self).__init__(namespace)
+        self.lock_dir = None  # MongoDB uses mongo itself for locking.
 
-        self.mongo = MongoDBNamespaceManager.clients.get(data_key,
-            _create_mongo_conn)
+        if pymongo is None:
+            raise RuntimeError('pymongo3 is not available')
 
-    def get_creation_lock(self, key):
-        """@TODO - stop hitting filesystem for this...
-        I think mongo can properly avoid dog piling for us.
-        """
-        return null_synchronizer()
-
-    def do_remove(self):
-        """Clears the entire filesystem (drops the collection)"""
-        log.debug("[MongoDB] Remove namespace: %s" % self.namespace)
-        q = {}
-        if self._sparse:
-            q = {'_id.namespace': self.namespace}
+        if isinstance(url, string_type):
+            self.client = MongoNamespaceManager.clients.get(url, pymongo.MongoClient, url)
         else:
-            q = {'_id': self.namespace}
-
-        log.debug("[MongoDB] Remove Query: %s" % q)
-        self.mongo.remove(q)
+            self.client = url
+        self.db = self.client.get_default_database()
+
+    def _format_key(self, key):
+        if not isinstance(key, str):
+            key = key.decode('ascii')
+        if len(key) > (self.MAX_KEY_LENGTH - len(self.namespace) - 1):
+            if not PY2:
+                key = key.encode('utf-8')
+            key = sha1(key).hexdigest()
+        return '%s:%s' % (self.namespace, key)
 
+    def get_creation_lock(self, key):
+        return MongoSynchronizer(self._format_key(key), self.client)
 
     def __getitem__(self, key):
-        log.debug("[MongoDB %s] Get Key: %s" % (self.mongo,
-                                                key))
-
-        _id = {}
-        fields = {}
-        if self._sparse:
-            _id = {
-                'namespace': self.namespace,
-                'key': key
-            }
-            fields['data'] = True
-        else:
-            _id = self.namespace
-            fields['data.' + key] = True
-
-        log.debug("[MongoDB] Get Query: id == %s Fields: %s", _id, fields)
-        result = self.mongo.find_one({'_id': _id}, fields=fields)
-        log.debug("[MongoDB] Get Result: %s", result)
-
-        if result:
-            """Running into instances in which mongo is returning
-            -1, which causes an error as __len__ should return 0
-            or positive integers, hence the check of size explicit"""
-            log.debug("Result: %s", result)
-            data = result.get('data', None)
-            log.debug("Data: %s", data)
-            if self._sparse:
-                value = data
-            else:
-                value = data.get(key, None)
-
-            if not value:
-                return None
-
-            if self._pickle or key == 'session':
-                value = _depickle(value)
-            else:
-                if value['pickled']:
-                    value = (value['stored'], value['expires'], _depickle(value['value']))
-                else:
-                    value = (value['stored'], value['expires'], value['value'])
-
-            log.debug("[key: %s] Value: %s" % (key, value))
-
-            return value
-        else:
-            return None
-
+        self._clear_expired()
+        entry = self.db.backer_cache.find_one({'_id': self._format_key(key)})
+        if entry is None:
+            raise KeyError(key)
+        return pickle.loads(entry['value'])
 
     def __contains__(self, key):
-        def _has():
-            result = self.__getitem__(key)
-            if result:
-                log.debug("[MongoDB] %s == %s" % (key, result))
-                return result is not None
-            else:
-                return False
-
-        log.debug("[MongoDB] Has '%s'? " % key)
-        ret = _has()
-
-
-        return ret
+        self._clear_expired()
+        entry = self.db.backer_cache.find_one({'_id': self._format_key(key)})
+        return entry is not None
 
     def has_key(self, key):
         return key in self
 
     def set_value(self, key, value, expiretime=None):
-        log.debug("[MongoDB %s] Set Key: %s (Expiry: %s) ... " %
-                  (self.mongo, key, expiretime))
+        self._clear_expired()
 
-        _id = {}
-        doc = {}
+        expiration = None
+        if expiretime is not None:
+            expiration = time.time() + expiretime
 
-        if self._pickle or key == 'session':
-            try:
-                value = pickle.dumps(value)
-            except:
-                log.exception("Failed to pickle value.")
-        else:
-            value = {
-                'stored': value[0],
-                'expires': value[1],
-                'value': value[2],
-                'pickled': False
-            }
-            try:
-                bson.BSON.encode(value)
-            except:
-                log.warning("Value is not bson serializable, pickling inner value.")
-                value['value'] = pickle.dumps(value['value'])
-                value['pickled'] = True
+        value = pickle.dumps(value)
+        self.db.backer_cache.update_one({'_id': self._format_key(key)},
+                                        {'$set': {'value': bson.Binary(value),
+                                                  'expiration': expiration}},
+                                        upsert=True)
+
+    def __setitem__(self, key, value):
+        self.set_value(key, value)
+
+    def __delitem__(self, key):
+        self._clear_expired()
+        self.db.backer_cache.delete_many({'_id': self._format_key(key)})
 
+    def do_remove(self):
+        self.db.backer_cache.delete_many({'_id': {'$regex': '^%s' % self.namespace}})
 
+    def keys(self):
+        return [e['key'].split(':', 1)[-1] for e in self.db.backer_cache.find_all(
+            {'_id': {'$regex': '^%s' % self.namespace}}
+        )]
 
-        if self._sparse:
-            _id = {
-                'namespace': self.namespace,
-                'key': key
-            }
+    def _clear_expired(self):
+        now = time.time()
+        self.db.backer_cache.delete_many({'_id': {'$regex': '^%s' % self.namespace},
+                                          'expiration': {'$ne': None, '$lte': now}})
 
-            doc['data'] = bson.Binary(value)
-            doc['_id'] = _id
-            if expiretime:
-                # TODO - What is the datatype of this? it should be instantiated as a datetime instance
-                doc['valid_until'] = expiretime
-        else:
-            _id = self.namespace
-            doc['$set'] = {'data.' + key: bson.Binary(value)}
-            if expiretime:
-                # TODO - What is the datatype of this? it should be instantiated as a datetime instance
-                doc['$set']['valid_until'] = expiretime
 
-        log.debug("Upserting Doc '%s' to _id '%s'" % (doc, _id))
-        self.mongo.update({"_id": _id}, doc, upsert=True, safe=True)
+class MongoSynchronizer(SynchronizerImpl):
+    """Provides a Writer/Reader lock based on MongoDB.
 
-    def __setitem__(self, key, value):
-        self.set_value(key, value)
+    Provided ``url`` can be both a mongodb connection string or
+    an already existing MongoClient instance.
 
-    def __delitem__(self, key):
-        """Delete JUST the key, by setting it to None."""
-        if self._sparse:
-            self.mongo.remove({'_id.namespace': self.namespace})
-        else:
-            self.mongo.update({'_id': self.namespace},
-                    {'$unset': {'data.' + key: True}}, upsert=False)
+    The data will be stored into ``beaker_locks`` collection of the
+    *default database*, so make sure your connection string or
+    MongoClient point to a default database.
 
-    def keys(self):
-        if self._sparse:
-            return [row['_id']['field'] for row in self.mongo.find({'_id.namespace': self.namespace}, {'_id': True})]
+    Locks are identified by local machine, PID and threadid, so
+    are suitable for use in both local and distributed environments.
+    """
+    # If a cache entry generation function can take a lot,
+    # but 15 minutes is more than a reasonable time.
+    LOCK_EXPIRATION = 900
+    MACHINE_ID = machine_identifier()
+
+    def __init__(self, identifier, url):
+        super(MongoSynchronizer, self).__init__()
+        self.identifier = identifier
+        if isinstance(url, string_type):
+            self.client = MongoNamespaceManager.clients.get(url, pymongo.MongoClient, url)
         else:
-            return self.mongo.find_one({'_id': self.namespace}, {'data': True}).get('data', {})
+            self.client = url
+        self.db = self.client.get_default_database()
+
+    def _clear_expired_locks(self):
+        now = datetime.datetime.utcnow()
+        expired = now - datetime.timedelta(seconds=self.LOCK_EXPIRATION)
+        self.db.beaker_locks.delete_many({'_id': self.identifier, 'timestamp': {'$lte': expired}})
+        return now
+
+    def _get_owner_id(self):
+        return '%s-%s-%s' % (self.MACHINE_ID, os.getpid(), threading.current_thread().ident)
+
+    def do_release_read_lock(self):
+        owner_id = self._get_owner_id()
+        self.db.beaker_locks.update_one({'_id': self.identifier, 'readers': owner_id},
+                                        {'$pull': {'readers': owner_id}})
+
+    def do_acquire_read_lock(self, wait):
+        now = self._clear_expired_locks()
+        owner_id = self._get_owner_id()
+        while True:
+            try:
+                self.db.beaker_locks.update_one({'_id': self.identifier, 'owner': None},
+                                                {'$set': {'timestamp': now},
+                                                 '$push': {'readers': owner_id}},
+                                                upsert=True)
+                return True
+            except pymongo.errors.DuplicateKeyError:
+                if not wait:
+                    return False
+                time.sleep(0.2)
+
+    def do_release_write_lock(self):
+        self.db.beaker_locks.delete_one({'_id': self.identifier, 'owner': self._get_owner_id()})
+
+    def do_acquire_write_lock(self, wait):
+        now = self._clear_expired_locks()
+        owner_id = self._get_owner_id()
+        while True:
+            try:
+                self.db.beaker_locks.update_one({'_id': self.identifier, 'owner': None,
+                                                 'readers': []},
+                                                {'$set': {'owner': owner_id,
+                                                          'timestamp': now}},
+                                                upsert=True)
+                return True
+            except pymongo.errors.DuplicateKeyError:
+                if not wait:
+                    return False
+                time.sleep(0.2)
 
-class MongoDBContainer(Container):
-    namespace_class = MongoDBNamespaceManager
 
 def _partition(source, sub):
     """Our own string partitioning method.
@@ -499,6 +458,6 @@ def _parse_uri(uri, default_port=27017):
 def _depickle(value):
     try:
         return pickle.loads(value)
-    except Exception, e:
+    except Exception as e:
         log.exception("Failed to unpickle value '{0}'.".format(e))
         return None
diff --git a/patzilla/util/database/beaker_mongodb_gridfs.py b/patzilla/util/database/beaker_mongodb_gridfs.py
index 605a0c70..e9aff35f 100644
--- a/patzilla/util/database/beaker_mongodb_gridfs.py
+++ b/patzilla/util/database/beaker_mongodb_gridfs.py
@@ -1,5 +1,8 @@
+import pickle
+import logging as log
 from mongodb_gridfs_beaker import MongoDBGridFSNamespaceManager, log, pickle
 
+
 def includeme(config):
 
     # Monkey patch 3rd party class to fix runtime error
diff --git a/patzilla/util/date/__init__.py b/patzilla/util/date/__init__.py
index a683524f..4be8b63a 100644
--- a/patzilla/util/date/__init__.py
+++ b/patzilla/util/date/__init__.py
@@ -111,7 +111,7 @@ def parse_date_within(value):
     """
     value = value.replace('within', '').strip().strip('"')
     parts = value.split(',')
-    parts = map(unicode.strip, parts)
+    parts = list(map(str.strip, parts))
     result = {
         'startdate': parts[0],
         'enddate': parts[1],
@@ -123,12 +123,12 @@ def year_range_to_within(value):
     Parse year ranges like "1990-2014" or "1990 - 2014"
     and convert into "within 1990,2014" expression
     """
-    if value.count(u'-') == 1:
-        parts = value.split(u'-')
+    if value.count('-') == 1:
+        parts = value.split('-')
         parts = [part.strip() for part in parts]
         year_from, year_to = parts
         if len(year_from) == 4 and len(year_to) == 4:
-            value = u'within {year_from},{year_to}'.format(**locals())
+            value = 'within {year_from},{year_to}'.format(**locals())
     return value
 
 def week_range(date):
diff --git a/patzilla/util/email/core.py b/patzilla/util/email/core.py
index 899b3c72..8e14d2cd 100644
--- a/patzilla/util/email/core.py
+++ b/patzilla/util/email/core.py
@@ -17,7 +17,7 @@
 log = logging.getLogger(__name__)
 
 
-def build_email(mail_to, subject, body_text, mail_from=u'test@example.org', reply_to=None, attachments=None, mime_headers=None):
+def build_email(mail_to, subject, body_text, mail_from='test@example.org', reply_to=None, attachments=None, mime_headers=None):
     """
     Flexible Multipart MIME message builder.
 
@@ -53,11 +53,11 @@ def build_email(mail_to, subject, body_text, mail_from=u'test@example.org', repl
     }
 
     # Subject header
-    mime_headers.update({u'Subject': Header(s=subject, charset='utf-8')})
+    mime_headers.update({'Subject': Header(s=subject, charset='utf-8')})
 
 
     # Add address headers
-    for key, item in address_headers.iteritems():
+    for key, item in address_headers.items():
         if isinstance(item, AddressList):
 
             # v1
@@ -70,7 +70,7 @@ def build_email(mail_to, subject, body_text, mail_from=u'test@example.org', repl
                 message[key] = value
 
     # Add more headers
-    for key, value in mime_headers.iteritems():
+    for key, value in mime_headers.items():
         #message.add_header(key, value)
         if value:
             message[key] = value
@@ -97,7 +97,7 @@ def build_email(mail_to, subject, body_text, mail_from=u'test@example.org', repl
     #            multipart attachments
     # ------------------------------------------
     # from https://docs.python.org/2/library/email-examples.html
-    for filename, payload in attachments.iteritems():
+    for filename, payload in attachments.items():
 
         # Guess the content type based on the file's extension.  Encoding
         # will be ignored, although we should check for simple things like
@@ -149,10 +149,10 @@ def build_email(mail_to, subject, body_text, mail_from=u'test@example.org', repl
     return payload
 
 
-def send_email(mail_to, message, smtp_settings=None, mail_from=u'test@example.org'):
+def send_email(mail_to, message, smtp_settings=None, mail_from='test@example.org'):
 
     smtp_settings = smtp_settings or {}
-    smtp_settings.setdefault('hostname', u'localhost')
+    smtp_settings.setdefault('hostname', 'localhost')
     smtp_settings.setdefault('port', 25)
 
     # sanity checks
@@ -191,7 +191,7 @@ def send_email(mail_to, message, smtp_settings=None, mail_from=u'test@example.or
 
 def format_addresslist(addresslist):
     #print 'addresslist:', addresslist.addresslist
-    return map(formataddr, addresslist.addresslist)
+    return list(map(formataddr, addresslist.addresslist))
 
 
 def fix_addresslist(addresslist):
diff --git a/patzilla/util/email/message.py b/patzilla/util/email/message.py
index 7baca1ee..37f7ea62 100644
--- a/patzilla/util/email/message.py
+++ b/patzilla/util/email/message.py
@@ -6,7 +6,7 @@
 import logging
 import textwrap
 from copy import deepcopy
-from core import build_email, send_email
+from .core import build_email, send_email
 from patzilla.util.config import read_config, to_list
 
 log = logging.getLogger(__name__)
@@ -38,25 +38,25 @@ def add_reply(self, address):
 
     def send(self, subject='', message='', files=None):
 
-        recipients = u', '.join(self.recipients)
-        reply_to = u', '.join(self.reply_to)
+        recipients = ', '.join(self.recipients)
+        reply_to = ', '.join(self.reply_to)
         files = files or {}
 
         # get smtp addressing information from settings
-        smtp_host = self.smtp_settings.get('hostname', u'localhost')
-        mail_from = self.email_settings['addressbook'].get('from', u'test@example.org')
+        smtp_host = self.smtp_settings.get('hostname', 'localhost')
+        mail_from = self.email_settings['addressbook'].get('from', 'test@example.org')
 
         # log smtp settings
         smtp_settings_log = deepcopy(self.smtp_settings)
         if 'password' in smtp_settings_log:
             del smtp_settings_log['password']
-        log.info(u'Sending email to "{recipients}". smtp settings: {smtp_settings}'.format(
+        log.info('Sending email to "{recipients}". smtp settings: {smtp_settings}'.format(
             recipients=recipients, smtp_settings=smtp_settings_log))
 
         # build subject
         event_date = time.strftime('%Y-%m-%d')
         event_time = time.strftime('%H:%M:%S')
-        subject_real = u''
+        subject_real = ''
         if 'subject_prefix' in self.email_settings['content']:
             prefix = self.email_settings['content'].get('subject_prefix')
             if not prefix.endswith(' '):
@@ -64,14 +64,14 @@ def send(self, subject='', message='', files=None):
             subject_real += prefix
 
         #subject_real += u'{subject} on {event_date} at {event_time}'.format(**locals())
-        subject_real += u'{}'.format(subject)
+        subject_real += '{}'.format(subject)
 
-        filenames = u'\n'.join([u'- ' + entry for entry in files.keys()])
+        filenames = '\n'.join(['- ' + entry for entry in list(files.keys())])
 
         body_template = textwrap.dedent(self.email_settings['content'].get('body', '')).strip()
 
         if 'signature' in self.email_settings['content']:
-            body_template += u'\n\n--\n' + textwrap.dedent(self.email_settings['content']['signature']).strip()
+            body_template += '\n\n--\n' + textwrap.dedent(self.email_settings['content']['signature']).strip()
 
         body_template = body_template.replace('\\n', '\r')
 
@@ -96,11 +96,11 @@ def send(self, subject='', message='', files=None):
             #   smtplib.SMTPServerDisconnected: Connection unexpectedly closed
             #
             send_email(recipients, message, smtp_settings=self.smtp_settings, mail_from=mail_from)
-            log.info(u'Email to recipients "{recipients}" sent successfully'.format(recipients=recipients))
+            log.info('Email to recipients "{recipients}" sent successfully'.format(recipients=recipients))
 
         except Exception as ex:
             # TODO: catch traceback when running in commandline mode
-            log.error(u'Error sending email: {failure}'.format(failure=ex))
+            log.error('Error sending email: {failure}'.format(failure=ex))
             raise
 
 
@@ -123,10 +123,10 @@ def send(self, subject='', message='', files=None):
     message = EmailMessage(settings['smtp'], settings['email'], {'subject_prefix': 'acme-product'})
     message.add_recipient('test@example.org')
     message.send(
-        subject     = u'Self-test email from Räuber Hotzenplotz',
-        message     = u'Self-test email from Räuber Hotzenplotz',
+        subject     = 'Self-test email from Räuber Hotzenplotz',
+        message     = 'Self-test email from Räuber Hotzenplotz',
         files       = {
-            u'test.txt':  u'☠☠☠ SKULL AND CROSSBONES ☠☠☠',
-            u'test.json': json.dumps(u'☠☠☠ SKULL AND CROSSBONES ☠☠☠'),
+            'test.txt':  '☠☠☠ SKULL AND CROSSBONES ☠☠☠',
+            'test.json': json.dumps('☠☠☠ SKULL AND CROSSBONES ☠☠☠'),
             }
     )
diff --git a/patzilla/util/expression/__init__.py b/patzilla/util/expression/__init__.py
index e96ed902..43dbceac 100644
--- a/patzilla/util/expression/__init__.py
+++ b/patzilla/util/expression/__init__.py
@@ -28,8 +28,8 @@ class SearchExpression(object):
 
     def parse_expression(self, query):
 
-        logger.info(u'Parsing search expression "{query}" with syntax "{syntax}" and grammar "{grammar}"'.format(
-            query=query, syntax=self.syntax, grammar=self.grammar and self.grammar.__name__ or u'default'))
+        logger.info('Parsing search expression "{query}" with syntax "{syntax}" and grammar "{grammar}"'.format(
+            query=query, syntax=self.syntax, grammar=self.grammar and self.grammar.__name__ or 'default'))
 
         if self.syntax == 'cql':
             self.parse_expression_cql(query)
@@ -40,8 +40,8 @@ def parse_expression(self, query):
     def parse_expression_cql(self, expression):
 
         # Fixup query: Wrap into quotes if CQL expression is a) unspecific, b) contains spaces and c) is still unquoted
-        if should_be_quoted(expression) and u'within' not in expression:
-            expression = u'"%s"' % expression
+        if should_be_quoted(expression) and 'within' not in expression:
+            expression = '"%s"' % expression
 
         # Parse and recompile CQL query string to apply number normalization
         query_object = None
@@ -59,11 +59,11 @@ def parse_expression_cql(self, expression):
                 expression = query_recompiled
 
             if query_recompiled != expression:
-                logger.info(u'Recompiled search expression to "{query}"'.format(query=expression))
+                logger.info('Recompiled search expression to "{query}"'.format(query=expression))
 
         except Exception as ex:
             # TODO: Can we get more details from diagnostic information to just stop here w/o propagating obviously wrong query to OPS?
-            logger.warn(u'CQL parse error: query="{0}", reason={1}, Exception was:\n{2}'.format(expression, ex, _exception_traceback()))
+            logger.warn('CQL parse error: query="{0}", reason={1}, Exception was:\n{2}'.format(expression, ex, _exception_traceback()))
 
         self.cql_parser = query_object
         self.expression = expression
diff --git a/patzilla/util/expression/keywords.py b/patzilla/util/expression/keywords.py
index e5bd7b3b..bfb3f422 100644
--- a/patzilla/util/expression/keywords.py
+++ b/patzilla/util/expression/keywords.py
@@ -64,7 +64,7 @@ def scan_keywords(op, keywords):
         #print "op.index:", op.index
         #print "op.term:", op.term
         if str(op.index) in keyword_fields:
-            keyword = clean_keyword(unicode(op.term))
+            keyword = clean_keyword(str(op.term))
             keywords.append(keyword)
 
     hasattr(op, 'leftOperand') and scan_keywords(op.leftOperand, keywords)
@@ -76,7 +76,7 @@ def keywords_to_response(request, search):
     Propagate keywords to client for highlighting
     """
 
-    logger.info(u'Propagating keywords from "{origin}": {keywords}'.format(
+    logger.info('Propagating keywords from "{origin}": {keywords}'.format(
         origin=search.keywords_origin, keywords=search.keywords))
 
     request.response.headers['X-PatZilla-Query-Keywords'] = json.dumps(search.keywords)
diff --git a/patzilla/util/image/convert.py b/patzilla/util/image/convert.py
index 63e53dee..2c6ccbee 100644
--- a/patzilla/util/image/convert.py
+++ b/patzilla/util/image/convert.py
@@ -3,13 +3,13 @@
 import os
 import shutil
 import tempfile
-from pathlib2 import Path
+from pathlib import Path
 
 import requests
 import where
 import logging
 import datetime
-import StringIO
+import io
 import subprocess
 from six import BytesIO
 from tempfile import NamedTemporaryFile
@@ -195,7 +195,7 @@ def run_imagemagick(command, input=None):
 
 def png_resize(png_payload, width):
 
-    image = Image.open(StringIO.StringIO(png_payload)).convert('RGB')
+    image = Image.open(io.StringIO(png_payload)).convert('RGB')
 
     image_width = image.size[0]
     image_height = image.size[1]
@@ -209,13 +209,13 @@ def png_resize(png_payload, width):
     #size = (int(width), int(image_height * aspect))
     size = (int(width), int(image_height / scale_factor))
     #print "size:", size
-    print "Resizing image from %s to %s" % (image.size, size)
+    print("Resizing image from %s to %s" % (image.size, size))
 
     image.thumbnail(size, Image.ANTIALIAS)
     #image.resize(size, Image.ANTIALIAS)
     #print "thumbnail done"
 
-    png = StringIO.StringIO()
+    png = io.StringIO()
     image.save(png, 'PNG')
     #print "image saved to memory"
 
diff --git a/patzilla/util/ipc/parser.py b/patzilla/util/ipc/parser.py
index e8701e54..e94d54a9 100644
--- a/patzilla/util/ipc/parser.py
+++ b/patzilla/util/ipc/parser.py
@@ -10,7 +10,7 @@ def decodeMatchToDict(match, key_suffix):
     if match:
         # transfer data from match groups to instance variable,
         # making all values uppercase
-        for key, value in match.groupdict().iteritems():
+        for key, value in match.groupdict().items():
             if key.endswith(key_suffix):
                 key = key.replace(key_suffix, '')
                 if value:
@@ -56,7 +56,7 @@ def decode(self):
         m = self.r.match(self.raw)
         self.ipc = decodeMatchToDict(m, '__1')
         if not self.ipc:
-            raise ValueError, "IPCR class '%s' could not be decoded" % self.raw
+            raise ValueError("IPCR class '%s' could not be decoded" % self.raw)
 
     def fix(self):
 
@@ -82,7 +82,7 @@ def asDict(self):
 
     def formatFlexible(self, class_padding='', group_subgroup_delimiter='', group_padding='', subgroup_padding=''):
         if not self.ipc['section']:
-            raise ValueError, "IPCR class '%s' could not be formatted" % self.raw
+            raise ValueError("IPCR class '%s' could not be formatted" % self.raw)
 
         ipc_serialized = self.ipc['section']
 
diff --git a/patzilla/util/network/browser.py b/patzilla/util/network/browser.py
index 51f61cc1..3545dbff 100644
--- a/patzilla/util/network/browser.py
+++ b/patzilla/util/network/browser.py
@@ -1,4 +1,4 @@
 # -*- coding: utf-8 -*-
 # (c) 2017-2019 Andreas Motl <andreas.motl@ip-tools.org>
 
-regular_user_agent = u'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:107.0) Gecko/20100101 Firefox/107.0'
+regular_user_agent = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:107.0) Gecko/20100101 Firefox/107.0'
diff --git a/patzilla/util/network/requests_xmlrpclib.py b/patzilla/util/network/requests_xmlrpclib.py
index 18dbbc2b..e61eaf61 100644
--- a/patzilla/util/network/requests_xmlrpclib.py
+++ b/patzilla/util/network/requests_xmlrpclib.py
@@ -6,17 +6,14 @@
 
 Usage:
 
-    >>> import xmlrpclib
+    >>> import xmlrpc.client
     >>> #from transport import RequestsTransport
-    >>> s = xmlrpclib.ServerProxy('http://yoursite.com/xmlrpc', transport=RequestsTransport())
+    >>> s = xmlrpc.client.ServerProxy('http://yoursite.com/xmlrpc', transport=RequestsTransport())
     >>> #s.demo.sayHello()
     Hello!
 """
-try:
-    import xmlrpc.client as xmlrpc
-except ImportError:
-    import xmlrpclib as xmlrpc
 
+import xmlrpc.client as xmlrpc
 import requests
 
 class RequestsTransport(xmlrpc.Transport):
diff --git a/patzilla/util/numbers/common.py b/patzilla/util/numbers/common.py
index ac5af45a..f44f1e25 100644
--- a/patzilla/util/numbers/common.py
+++ b/patzilla/util/numbers/common.py
@@ -3,7 +3,7 @@
 import re
 import types
 import logging
-from patzilla.util.data.container import SmartBunch
+from patzilla.util.data.container import SmartMunch
 from patzilla.util.numbers.helper import strip_spaces
 
 """
@@ -13,7 +13,7 @@
 log = logging.getLogger(__name__)
 
 
-class DocumentIdentifierBunch(SmartBunch):
+class DocumentIdentifierBunch(SmartMunch):
 
     def __str__(self):
         return self.dump()
@@ -29,12 +29,12 @@ def join_patent(patent):
     return number
 
 def decode_patent_number(patent):
-    if isinstance(patent, types.StringTypes):
+    if isinstance(patent, (str,)):
         decoded = split_patent_number(patent)
-    elif isinstance(patent, types.DictionaryType):
+    elif isinstance(patent, dict):
         decoded = patent
     else:
-        raise TypeError(u'Document number "{patent}" of type "{type}" could not be decoded'.format(patent=patent, type=type(patent)))
+        raise TypeError('Document number "{patent}" of type "{type}" could not be decoded'.format(patent=patent, type=type(patent)))
     return decoded
 
 def split_patent_number(patent_number):
@@ -154,7 +154,7 @@ def split_patent_number(patent_number):
         return dib
 
     else:
-        log.error(u'Unable to parse patent number "{0}"'.format(patent_number))
+        log.error('Unable to parse patent number "{0}"'.format(patent_number))
 
 
 def split_patent_number_more(patent):
diff --git a/patzilla/util/numbers/denormalize.py b/patzilla/util/numbers/denormalize.py
index 6395e2a6..9b4deee2 100644
--- a/patzilla/util/numbers/denormalize.py
+++ b/patzilla/util/numbers/denormalize.py
@@ -121,16 +121,16 @@ def test_denormalization():
 WO1990004917
 """
 
-    print "-" * 30
-    print "original\tdenormalized"
-    print "-" * 30
+    print("-" * 30)
+    print("original\tdenormalized")
+    print("-" * 30)
     for number in payload.split("\n"):
         if not number or number == "\n": continue
         if number.startswith('---'):
-            print number
+            print(number)
             continue
         number_denormalized = join_patent(denormalize_patent(split_patent_number(number)))
-        print "%s\t%s" % (number, number_denormalized)
+        print("%s\t%s" % (number, number_denormalized))
 
 
 if __name__ == "__main__":
diff --git a/patzilla/util/numbers/helper.py b/patzilla/util/numbers/helper.py
index 044ba815..520c49fc 100644
--- a/patzilla/util/numbers/helper.py
+++ b/patzilla/util/numbers/helper.py
@@ -22,11 +22,11 @@ def strip_spaces(number):
     number = r_invalid.sub('', number)
     return number
 
-def read_numbersfile(file):
-    fh = open(file, 'r')
+def read_numbersfile(_file):
+    fh = open(_file, 'r')
     numbers_raw = fh.readlines()
     fh.close()
-    numbers = map(lambda number: number.strip(" ;\"'\t\n\r"), numbers_raw)
+    numbers = [number.strip(" ;\"'\t\n\r") for number in numbers_raw]
     numbers = [number for number in numbers if number and not number.startswith('#')]
     return numbers
 
diff --git a/patzilla/util/numbers/normalize.py b/patzilla/util/numbers/normalize.py
index 1dd5da49..0b60f9d9 100644
--- a/patzilla/util/numbers/normalize.py
+++ b/patzilla/util/numbers/normalize.py
@@ -194,7 +194,7 @@ def normalize_patent(number, as_dict=False, as_string=False, fix_kindcode=False,
         provider = 'ops'
 
     # 1. handle patent dicts or convert (split) from string
-    if isinstance(number, types.DictionaryType):
+    if isinstance(number, dict):
         patent = number
     else:
         patent = split_patent_number(number)
@@ -209,7 +209,7 @@ def normalize_patent(number, as_dict=False, as_string=False, fix_kindcode=False,
     # 3. result handling
 
     # 3.a) default mechanism: return what we've got
-    if isinstance(number, types.DictionaryType):
+    if isinstance(number, dict):
         result = patent_normalized
     else:
         result = join_patent(patent_normalized)
@@ -622,7 +622,7 @@ def normalize_patent_it(patent):
 
     # filter: special document handling (with alphanumeric prefixes)
     # trim and pad sequential number with zeros to get total length of 7 characters for patent number
-    if patched.has_key('number-type') and patched.has_key('number-real'):
+    if 'number-type' in patched and 'number-real' in patched:
         subtype = patched['number-type']
         seqnumber = patched['number-real']
         patched['number'] = subtype + seqnumber.lstrip('0')
@@ -671,16 +671,16 @@ def normalization_example():  # pragma: nocover
         'JP3657641B2',
     ]
 
-    print "-" * 30
-    print '{0}{1}'.format("original".ljust(20), "normalized")
-    print "-" * 30
+    print("-" * 30)
+    print('{0}{1}'.format("original".ljust(20), "normalized"))
+    print("-" * 30)
     for number in numbers:
         if number.find('---') != -1:
-            print number
+            print(number)
             continue
         result = normalize_patent(number)
         #result = join_patent(patch_patent_old_archive(patent))
-        print "{0}{1}".format(number.ljust(20), result)
+        print("{0}{1}".format(number.ljust(20), result))
 
 
 if __name__ == "__main__":  # pragma: nocover
diff --git a/patzilla/util/numbers/numberlists.py b/patzilla/util/numbers/numberlists.py
index d6341e32..22ceb2ad 100644
--- a/patzilla/util/numbers/numberlists.py
+++ b/patzilla/util/numbers/numberlists.py
@@ -4,13 +4,13 @@
 from patzilla.util.numbers.normalize import normalize_patent
 
 def parse_numberlist(rawdata):
-    pattern = re.compile(u'[,\n]')
+    pattern = re.compile('[,\n]')
     entries = pattern.split(rawdata)
-    entries = map(unicode.strip, entries)
+    entries = list(map(str.strip, entries))
     return entries
 
 def normalize_numbers(entries):
-    entries = map(lambda s: s.replace(u' ', u''), entries)
+    entries = [s.replace(' ', '') for s in entries]
     response = {'valid': [], 'invalid': [], 'all': []}
     for entry in entries:
         entry_normalized = normalize_patent(entry, fix_kindcode=True)
diff --git a/patzilla/util/python/__init__.py b/patzilla/util/python/__init__.py
index 4974efcc..5a69667c 100644
--- a/patzilla/util/python/__init__.py
+++ b/patzilla/util/python/__init__.py
@@ -2,7 +2,7 @@
 # (c) 2014 Andreas Motl, Elmyra UG
 import sys
 import traceback
-from StringIO import StringIO
+from io import StringIO
 
 def exception_traceback(exc_info=None):
     """
diff --git a/patzilla/util/text/format.py b/patzilla/util/text/format.py
index ae59c647..9093becf 100644
--- a/patzilla/util/text/format.py
+++ b/patzilla/util/text/format.py
@@ -2,9 +2,9 @@
 # (c) 2014-2016 Andreas Motl, Elmyra UG
 import re
 
-_slugify_strip_re = re.compile(r'[^\w\s-]')
-_slugify_strip_wo_equals_re = re.compile(r'[^\w\s=-]')
-_slugify_hyphenate_re = re.compile(r'[-\s]+')
+_slugify_strip_re = re.compile(rb'[^\w\s-]')
+_slugify_strip_wo_equals_re = re.compile(rb'[^\w\s=-]')
+_slugify_hyphenate_re = re.compile(rb'[-\s]+')
 def slugify(value, strip_equals=True, lowercase=True):
     """
     Normalizes string, converts to lowercase, removes non-alpha characters,
@@ -15,19 +15,23 @@ def slugify(value, strip_equals=True, lowercase=True):
     Via http://code.activestate.com/recipes/577257-slugify-make-a-string-usable-in-a-url-or-filename/
     """
     import unicodedata
-    if not isinstance(value, unicode):
-        value = unicode(value)
+    if not isinstance(value, str):
+        value = str(value)
     value = unicodedata.normalize('NFKD', value).encode('ascii', 'ignore')
 
     _strip_re = _slugify_strip_re
     if not strip_equals:
         _strip_re = _slugify_strip_wo_equals_re
-    value = unicode(_strip_re.sub('', value).strip())
+    
+    if  isinstance(value, str):
+        value = _strip_re.sub('', value).strip()
+    else:
+        value = _strip_re.sub(b'', value).strip()
 
     if lowercase:
         value = value.lower()
 
-    value =  _slugify_hyphenate_re.sub('-', value)
+    value =  _slugify_hyphenate_re.sub(b'-', value)
     return value
 
 def text_indent(text, amount=4, ch=' '):
diff --git a/patzilla/util/web/email/submit.py b/patzilla/util/web/email/submit.py
index 2504401e..e8353e2e 100644
--- a/patzilla/util/web/email/submit.py
+++ b/patzilla/util/web/email/submit.py
@@ -5,7 +5,7 @@
 from validate_email import validate_email
 from pyramid.threadlocal import get_current_request
 from patzilla.util.config import read_config, read_list, to_list
-from patzilla.util.data.container import SmartBunch
+from patzilla.util.data.container import SmartMunch
 from patzilla.util.email.message import EmailMessage
 
 log = logging.getLogger(__name__)
@@ -68,23 +68,23 @@ def email_issue_report(report, recipients):
     recipients = to_list(recipients)
 
     identifier = None
-    if isinstance(report, SmartBunch):
+    if isinstance(report, SmartMunch):
         identifier = report.meta.id
 
     # Build reasonable subject
-    subject = u'Product issue'
+    subject = 'Product issue'
     if 'dialog' in report and 'what' in report.dialog:
-        subject = u'[{}] '.format(report.dialog.what) + subject
+        subject = '[{}] '.format(report.dialog.what) + subject
     if identifier:
-        subject += u' #' + identifier
+        subject += ' #' + identifier
 
     # Build reasonable message
-    message = u''
+    message = ''
     if 'dialog' in report and 'remark' in report.dialog:
         message = report.dialog.remark
 
     # Add JSON report as attachment
-    files = {u'report.json': report.pretty()}
+    files = {'report.json': report.pretty()}
 
     email = message_factory(recipients=recipients)
     email.send(
diff --git a/patzilla/util/web/identity/store.py b/patzilla/util/web/identity/store.py
index 92a69d45..982538e0 100644
--- a/patzilla/util/web/identity/store.py
+++ b/patzilla/util/web/identity/store.py
@@ -12,8 +12,8 @@
 from mongoengine.fields import StringField, ListField, DateTimeField, DictField
 from mongoengine.errors import NotUniqueError
 from pyramid.threadlocal import get_current_request
-from zope.interface.declarations import implements
 from zope.interface.interface import Interface
+from zope.interface import implementer
 
 log = logging.getLogger(__name__)
 
@@ -133,9 +133,10 @@ class UserMetrics(Document):
 class IUserMetricsManager(Interface):
     pass
 
+@implementer(IUserMetricsManager)
 class UserMetricsManager(object):
 
-    implements(IUserMetricsManager)
+# py27    implements(IUserMetricsManager)
 
     def measure_upstream(self, upstream, volume):
 
diff --git a/patzilla/util/web/pyramid/cornice.py b/patzilla/util/web/pyramid/cornice.py
index b7dadcae..89a6ee9b 100644
--- a/patzilla/util/web/pyramid/cornice.py
+++ b/patzilla/util/web/pyramid/cornice.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # (c) 2017 Andreas Motl, Elmyra UG
-from __future__ import absolute_import
+
 from cornice.errors import Errors
 
 def add_location_whitelisted(self, location, name=None, description=None, **kw):
diff --git a/patzilla/util/web/pyramid/renderer.py b/patzilla/util/web/pyramid/renderer.py
index 78a06af4..d941add6 100644
--- a/patzilla/util/web/pyramid/renderer.py
+++ b/patzilla/util/web/pyramid/renderer.py
@@ -18,7 +18,7 @@ def __call__(self, data, context):
         content_type = (context['request'].accept.best_match(acceptable)
                         or acceptable[0])
         response.content_type = content_type
-        print "data:", data
+        print("data:", data)
         return 'hello'
         #return json.dumps(data, use_decimal=True)
 
diff --git a/patzilla/util/web/util/xmlrpclib.py b/patzilla/util/web/util/xmlrpclib.py
index 50c5f6de..df3353b6 100644
--- a/patzilla/util/web/util/xmlrpclib.py
+++ b/patzilla/util/web/util/xmlrpclib.py
@@ -1,9 +1,9 @@
 # -*- coding: utf-8 -*-
 # (c) 2014-2015 Andreas Motl, Elmyra UG
-from __future__ import absolute_import
+
 import sys
 import socket
-import xmlrpclib
+import xmlrpc.client
 import ssl
 
 # https://stackoverflow.com/questions/372365/set-timeout-for-xmlrpclib-serverproxy/14397619#14397619
@@ -24,7 +24,7 @@ def __enter__(self):
             if self.__timeout:
                 self.__prevDefaultTimeout = socket.getdefaulttimeout()
                 socket.setdefaulttimeout(self.__timeout)
-            proxy = xmlrpclib.Server(self.__url, allow_none=True)
+            proxy = xmlrpc.client.Server(self.__url, allow_none=True)
 
         except Exception as ex:
             raise Exception("Unable create XMLRPC-proxy for url '%s': %s" % (self.__url, ex))
diff --git a/patzilla/util/web/uwsgi/uwsgidecorators.py b/patzilla/util/web/uwsgi/uwsgidecorators.py
index 79c08ea1..29b20c36 100644
--- a/patzilla/util/web/uwsgi/uwsgidecorators.py
+++ b/patzilla/util/web/uwsgi/uwsgidecorators.py
@@ -4,7 +4,7 @@
 from threading import Thread
 
 try:
-    import cPickle as pickle
+    import pickle as pickle
 except:
     import pickle
 
diff --git a/patzilla/util/xml/format.py b/patzilla/util/xml/format.py
index 49d32120..1ee0b738 100644
--- a/patzilla/util/xml/format.py
+++ b/patzilla/util/xml/format.py
@@ -69,5 +69,5 @@ def data(self, root):
         return super(BadgerFishNoNamespace, self).data(root)
 
     def clean_tag(self, node):
-        if isinstance(node.tag, basestring):
+        if isinstance(node.tag, str):
             node.tag = re.sub('{.*}', '', node.tag)
diff --git a/pserve.py b/pserve.py
new file mode 100644
index 00000000..4ddeca3f
--- /dev/null
+++ b/pserve.py
@@ -0,0 +1,10 @@
+#!/home/frank/DATA/Envs/env1/bin/python3
+# -*- coding: utf-8 -*-
+import regex as re
+import sys
+
+from pyramid.scripts.pserve import main
+
+if __name__ == '__main__':
+    sys.argv[0] = re.sub(r'(-script\.pyw?|\.exe)?$', '', sys.argv[0])
+    sys.exit(main())
diff --git a/setup.cfg b/setup.cfg
index 28b62b06..5622110a 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -13,6 +13,8 @@ addopts = -rA -vvv
     --app-cache-backend=filesystem
     patzilla tests -k 'not uspto'
 
+doctest_optionflags = NORMALIZE_WHITESPACE IGNORE_EXCEPTION_DETAIL
+
 log_level = DEBUG
 log_cli_level = DEBUG
 
diff --git a/setup.py b/setup.py
index e75bff7d..763fadec 100644
--- a/setup.py
+++ b/setup.py
@@ -10,7 +10,7 @@
     #   Environment
     # ----------------------------------------------
     'six>=1.10.0',
-    'mock>=3,<4',  # 4.0.3
+    'mock',
 
     # ----------------------------------------------
     #   Backend
@@ -41,9 +41,9 @@
     # Database and storage
     # Can't upgrade to pymongo-3.5.1 due to "from pymongo.connection import Connection"
     # usage in "mongodb_gridfs_beaker" module.
-    'pymongo<3',                # 3.13.0, 4.3.3
-    'mongodb_gridfs_beaker==0.5.4',
-    'mongoengine==0.13.0',      # 0.24.1
+    'pymongo',                  # 3.13.0, 4.3.3
+    'mongodb_gridfs_beaker@https://github.com/ip-tools/mongodb_gridfs_beaker/archive/0.6.0dev1.tar.gz#egg=mongodb_gridfs_beaker',
+    'mongoengine==0.20.0',      # 0.27.0
     'python-magic<1',
 
     # Web services
@@ -51,7 +51,7 @@
 
     # Authorization
     'pycryptodome>=3,<4',
-    'python-jwt>=3.3.4,<4',
+    'python-jwt',
     'pbkdf2==1.3',
 
 
@@ -73,8 +73,8 @@
     'ndg-httpsclient<1',
 
     # HTML
-    'BeautifulSoup<4',
-    'html2text==2016.9.19',     # 2020.1.16
+    'beautifulsoup4',
+    'html2text', 
 
     # XML
     # Remark: Both lxml 3.8.0 and 4.0.0 will segfault on Debian Wheezy (7.11)
@@ -92,19 +92,19 @@
 
     # Data handling
     'attrs',
-    'Bunch==1.0.1',             # Maybe switch to "Munch"
-    'pyparsing==2.0.2',         # 2.2.2, 2.3.1, 2.4.7, 3.0.8
+    'Munch',
+    'pyparsing<4',              # 3.0.9
     'python-dateutil<3',
     'ago==0.0.9',               # 0.0.93
     'arrow==0.10.0',            # 0.12.1
     'validate_email<2',
-    'numpy==1.16.6',            # 1.22.3
-    'pandas==0.18.1',           # 0.22.0, 0.25.3, 1.4.2
-    'pathlib2<3',
+    'numpy>=1.16.6',            # 1.22.3
+    'pandas',           # 0.22.0, 0.25.3, 1.4.2
+    'pathlib',
 
     # Data formatting
-    'openpyxl>=2.4.2,<3',
-    'xlrd==0.9.3',              # 0.9.4, 1.2.0, 2.0.1
+    'openpyxl',
+    'xlrd3',
     'XlsxWriter==0.9.3',        # 1.4.5, 2.0.0, 3.0.3
 
     # Data conversion
@@ -215,8 +215,6 @@
       extras_require={
           'test': test_requires,
       },
-      dependency_links=[
-      ],
 
       entry_points={
         'paste.app_factory': [
diff --git a/tests/__init__.py b/tests/__init__.py
index b06494c4..30067b0a 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -11,7 +11,7 @@ def suppress_warnings():
     """
     with warnings.catch_warnings():
         warnings.filterwarnings("ignore", category=DeprecationWarning)
-        import pandas.util.nosetester
+        import numpy.testing
 
 
 suppress_warnings()
diff --git a/tests/access/test_dpma_register.py b/tests/access/test_dpma_register.py
index ba2aa470..1180615e 100644
--- a/tests/access/test_dpma_register.py
+++ b/tests/access/test_dpma_register.py
@@ -37,10 +37,10 @@ def test_dpmaregister_url_de():
 def test_dpmaregister_xml():
     with F5WafWrapper():
         xml = access_register("WO2008034638", output_format="xml")
-        assert '<?xml version="1.0" encoding="UTF-8"?>' in xml
-        assert "<dpma-patent-document" in xml
-        assert "<bibliographic-data>" in xml
-        assert "<events>" in xml
+        assert b'<?xml version="1.0" encoding="UTF-8"?>' in xml
+        assert b"<dpma-patent-document" in xml
+        assert b"<bibliographic-data>" in xml
+        assert b"<events>" in xml
 
 
 def test_dpmaregister_json():
@@ -72,12 +72,12 @@ def test_dpmaregister_html_compact_de():
 def test_dpmaregister_pdf_compact_en():
     with F5WafWrapper():
         pdf = access_register("EP666666", output_format="pdf")
-        assert "File number 695 34 171.5" in pdf
-        assert "Most recent update in DPMAregister on Jan 7, 2017" in pdf
+        assert b"File number 695 34 171.5" in pdf
+        assert b"Most recent update in DPMAregister on Jan 7, 2017" in pdf
 
 
 def test_dpmaregister_pdf_compact_de():
     with F5WafWrapper():
         pdf = access_register("EP666666", output_format="pdf", language="de")
-        assert "Aktenzeichen 695 34 171.5" in pdf
-        assert "letzte Aktualisierung in DPMAregister am 07.01.2017" in pdf
+        assert b"Aktenzeichen 695 34 171.5" in pdf
+        assert b"letzte Aktualisierung in DPMAregister am 07.01.2017" in pdf
diff --git a/tests/access/test_epo_ops.py b/tests/access/test_epo_ops.py
index b30051e2..fead9461 100644
--- a/tests/access/test_epo_ops.py
+++ b/tests/access/test_epo_ops.py
@@ -50,7 +50,7 @@ def test_baseurl(app_request):
     response = client._make_request(
         OPS_BASE_URI, data={}, extra_headers={"Accept": "*"}, use_get=True,
     )
-    assert "<title>EPO - Open Patent Services (OPS)</title>" in response.content
+    assert b"<title>EPO - Open Patent Services (OPS)</title>" in response.content
 
 
 def test_search_full_success(app_request):
@@ -74,15 +74,15 @@ def test_search_biblio_compact_success(app_request):
     assert jpath('/0/pubdate', compact) == "1995-08-09"
     assert jpath('/1/pubnumber', compact) == "EP0666667"
     assert jpath('/1/pubdate', compact) == "1995-08-09"
-    assert compact[0].keys() == compact[1].keys() == [
+    assert sorted(compact[0].keys()) == sorted(compact[1].keys()) == [
+        'abstract',
         'appdate',
         'applicant',
-        'pubdate',
         'appnumber',
-        'title',
-        'abstract',
-        'pubnumber',
         'inventor',
+        'pubdate',
+        'pubnumber',
+        'title',
     ]
 
 
@@ -140,7 +140,7 @@ def test_search_swap_family(app_request):
     total_result_count = int(jpath('/ops:world-patent-data/ops:biblio-search/@total-result-count', results.data))
     assert total_result_count == 2
 
-    assert results.selected_numbers == [u'DE69534171T2', u'EP0666667A2']
+    assert results.selected_numbers == ['DE69534171T2', 'EP0666667A2']
 
 
 def test_crawl(app_request):
@@ -188,13 +188,13 @@ def test_biblio_data_json_success(app_request):
     assert len(documents) == 3
     assert kindcodes == ["A2", "A3", "B1"]
     assert attributes == [
-        u'@country',
-        u'@doc-number',
-        u'@family-id',
-        u'@kind',
-        u'@system',
-        u'abstract',
-        u'bibliographic-data',
+        '@country',
+        '@doc-number',
+        '@family-id',
+        '@kind',
+        '@system',
+        'abstract',
+        'bibliographic-data',
     ]
 
 
@@ -218,7 +218,7 @@ def test_biblio_data_xml_success(app_request):
     Proof getting bibliographic for a specific document in XML format works.
     """
     results = get_ops_biblio_data("publication", "EP0666666", xml=True)
-    assert results.startswith('<?xml version="1.0" encoding="UTF-8"?>')
+    assert results.startswith(b'<?xml version="1.0" encoding="UTF-8"?>')
 
 
 def test_document_kindcodes_success(app_request):
@@ -275,31 +275,31 @@ def test_family_members(app_request):
     pubnumbers = sorted([item["publication"]["number-docdb"] for item in members.items])
 
     assert appnumbers == [
-        u'CA2142029A',
-        u'CA2142029A',
-        u'DE69534171T',
-        u'DE69534171T',
-        u'EP95480005A',
-        u'EP95480005A',
-        u'EP95480005A',
-        u'JP29020894A',
-        u'JP29020894A',
-        u'US19288494A',
-        u'US47157195A',
+        'CA2142029A',
+        'CA2142029A',
+        'DE69534171T',
+        'DE69534171T',
+        'EP95480005A',
+        'EP95480005A',
+        'EP95480005A',
+        'JP29020894A',
+        'JP29020894A',
+        'US19288494A',
+        'US47157195A',
     ]
 
     assert pubnumbers == [
-        u'CA2142029A1',
-        u'CA2142029C',
-        u'DE69534171D1',
-        u'DE69534171T2',
-        u'EP0666666A2',
-        u'EP0666666A3',
-        u'EP0666666B1',
-        u'JP2613027B2',
-        u'JPH07231328A',
-        u'US5467352A',
-        u'US5572526A',
+        'CA2142029A1',
+        'CA2142029C',
+        'DE69534171D1',
+        'DE69534171T2',
+        'EP0666666A2',
+        'EP0666666A3',
+        'EP0666666B1',
+        'JP2613027B2',
+        'JPH07231328A',
+        'US5467352A',
+        'US5572526A',
     ]
 
 
@@ -435,8 +435,8 @@ def test_description_xml_success(app_request):
     Acquire full text "description" in XML format.
     """
     data = ops_description("EP666666A2", xml=True)
-    assert data.startswith('<?xml version="1.0" encoding="UTF-8"?>')
-    assert "The present invention generally relates to multi-node communication systems with shared resources." in data
+    assert data.startswith(b'<?xml version="1.0" encoding="UTF-8"?>')
+    assert b"The present invention generally relates to multi-node communication systems with shared resources." in data
 
 
 def test_description_failure(app_request):
@@ -485,8 +485,8 @@ def test_claims_xml_success(app_request):
     Acquire full text "claims" in XML format.
     """
     data = ops_claims("EP666666A2", xml=True)
-    assert data.startswith('<?xml version="1.0" encoding="UTF-8"?>')
-    assert "1. In a communication system having a plurality of nodes" in data
+    assert data.startswith(b'<?xml version="1.0" encoding="UTF-8"?>')
+    assert b"1. In a communication system having a plurality of nodes" in data
 
 
 def test_claims_failure(app_request):
@@ -531,7 +531,7 @@ def test_family_docdb_xml_success(app_request):
         document_number="EP0666666A2",
         constituents="biblio",
     )
-    assert response.startswith('<?xml version="1.0" encoding="UTF-8"?>')
+    assert response.startswith(b'<?xml version="1.0" encoding="UTF-8"?>')
 
 
 def test_family_docdb_xml_not_found_failure(app_request):
@@ -558,7 +558,7 @@ def test_register_json_success(app_request):
 
 def test_register_xml_success(app_request):
     response = ops_register(reference_type="publication", document_number="EP0666666A2", xml=True)
-    assert response.startswith('<?xml version="1.0" encoding="UTF-8" standalone="yes"?>')
+    assert response.startswith(b'<?xml version="1.0" encoding="UTF-8" standalone="yes"?>')
 
 
 def test_register_not_found_failure(app_request):
@@ -573,4 +573,4 @@ def test_register_not_found_failure(app_request):
 
 def test_service_usage(app_request):
     response = ops_service_usage("01/01/2022", "02/01/2022")
-    assert response.keys() == ["response-size", "time-range", "message-count"]
+    assert sorted(response.keys()) == ["message-count", "response-size", "time-range"]
diff --git a/tests/access/test_uspto.py b/tests/access/test_uspto.py
index f3503a3b..8852600d 100644
--- a/tests/access/test_uspto.py
+++ b/tests/access/test_uspto.py
@@ -6,7 +6,7 @@
 import re
 
 import pytest
-from bunch import Bunch
+from munch import Munch
 from pyramid.httpexceptions import HTTPNotFound
 
 from patzilla.access.uspto.image import fetch_first_drawing
@@ -161,9 +161,9 @@ def test_fetch_url_failure():
 
 
 def test_get_reference_type_valid():
-    assert get_reference_type(Bunch(number="2022110447")) == UsptoPdfReferenceType.APPLICATION
-    assert get_reference_type(Bunch(number="2548918")) == UsptoPdfReferenceType.PUBLICATION
-    assert get_reference_type(Bunch(number=1)) == UsptoPdfReferenceType.PUBLICATION
+    assert get_reference_type(Munch(number="2022110447")) == UsptoPdfReferenceType.APPLICATION
+    assert get_reference_type(Munch(number="2548918")) == UsptoPdfReferenceType.PUBLICATION
+    assert get_reference_type(Munch(number=1)) == UsptoPdfReferenceType.PUBLICATION
 
 
 def test_get_reference_type_invalid():
@@ -172,9 +172,9 @@ def test_get_reference_type_invalid():
     assert ex.match(re.escape("Unknown document reference type: None"))
 
     with pytest.raises(ValueError) as ex:
-        get_reference_type(Bunch())
+        get_reference_type(Munch())
     assert ex.match(re.escape("Unknown document reference type:"))
 
     with pytest.raises(ValueError) as ex:
-        get_reference_type(Bunch(number=None))
+        get_reference_type(Munch(number=None))
     assert ex.match(re.escape("Unknown document reference type:"))
diff --git a/tests/commands/test_commands_ops.py b/tests/commands/test_commands_ops.py
index c2830056..a6b63f4b 100644
--- a/tests/commands/test_commands_ops.py
+++ b/tests/commands/test_commands_ops.py
@@ -76,8 +76,8 @@ def test_command_ops_image_fulldocument_pdf_success():
     result = runner.invoke(cli, "ops image --document=EP0666666B1 --page=1", catch_exceptions=False)
     assert result.exit_code == 0
 
-    assert result.stdout.startswith("%PDF-1.4")
-    assert 30000 < len(result.stdout) < 50000
+    assert result.stdout_bytes.startswith(b"%PDF-1.4")
+    assert 30_000 < len(result.stdout_bytes) < 150_000
 
 
 def test_command_ops_image_fulldocument_tiff_success():
@@ -89,7 +89,7 @@ def test_command_ops_image_fulldocument_tiff_success():
     result = runner.invoke(cli, "ops image --document=EP0666666B1 --page=1 --format=tiff", catch_exceptions=False)
     assert result.exit_code == 0
 
-    assert result.stdout.startswith(b"\x4d\x4d\x00\x2a")
+    assert result.stdout_bytes.startswith(b"\x4d\x4d\x00\x2a")
 
 
 def test_command_ops_image_drawing_pdf_success():
@@ -101,8 +101,8 @@ def test_command_ops_image_drawing_pdf_success():
     result = runner.invoke(cli, "ops image --document=EP0666666B1 --kind=FullDocumentDrawing --page=1", catch_exceptions=False)
     assert result.exit_code == 0
 
-    assert result.stdout.startswith("%PDF-1.4")
-    assert 10000 < len(result.stdout) < 20000
+    assert result.stdout_bytes.startswith(b"%PDF-1.4")
+    assert 10_000 < len(result.stdout_bytes) < 20_000
 
 
 def test_command_ops_image_failure():
diff --git a/tests/test_numberlists.py b/tests/test_numberlists.py
index 860eb35a..63096e49 100644
--- a/tests/test_numberlists.py
+++ b/tests/test_numberlists.py
@@ -5,26 +5,26 @@ def test_parse_numberlist():
     """
     Proof that conveniently parsing a list of items works.
     """
-    assert parse_numberlist(u"foo , bar") == [u'foo', u'bar']
-    assert parse_numberlist(u"foo \n bar") == [u'foo', u'bar']
+    assert parse_numberlist("foo , bar") == ['foo', 'bar']
+    assert parse_numberlist("foo \n bar") == ['foo', 'bar']
 
 
 def test_normalize_numbers_valid():
     """
     Normalize a list of valid patent numbers.
     """
-    assert normalize_numbers([u'EP666666B1', u'EP1000000']) == {'all': [u'EP0666666B1', u'EP1000000'], 'invalid': [], 'valid': [u'EP0666666B1', u'EP1000000']}
+    assert normalize_numbers(['EP666666B1', 'EP1000000']) == {'all': ['EP0666666B1', 'EP1000000'], 'invalid': [], 'valid': ['EP0666666B1', 'EP1000000']}
 
 
 def test_normalize_numbers_invalid():
     """
     Normalize a list of invalid patent numbers.
     """
-    assert normalize_numbers([u'foo', u'bar']) == {'all': [u'foo', u'bar'], 'invalid': [u'foo', u'bar'], 'valid': []}
+    assert normalize_numbers(['foo', 'bar']) == {'all': ['foo', 'bar'], 'invalid': ['foo', 'bar'], 'valid': []}
 
 
 def test_normalize_numbers_mixed():
     """
     Normalize a list of both valid and invalid patent numbers.
     """
-    assert normalize_numbers([u'EP666666B1', u'foobar']) == {'all': [u'EP0666666B1', u'foobar'], 'invalid': [u'foobar'], 'valid': [u'EP0666666B1']}
+    assert normalize_numbers(['EP666666B1', 'foobar']) == {'all': ['EP0666666B1', 'foobar'], 'invalid': ['foobar'], 'valid': ['EP0666666B1']}
diff --git a/tests/util/test_jwt.py b/tests/util/test_jwt.py
index 9fb7f71e..c7204585 100644
--- a/tests/util/test_jwt.py
+++ b/tests/util/test_jwt.py
@@ -59,7 +59,7 @@ def test_signer_sign_invalid_expiration(jwt_signer):
     """
     with pytest.raises(ValueError) as ex:
         jwt_signer.sign("foo", ttl="bar")
-    assert ex.match("value=bar, type=<type 'str'> is an invalid JWT expiration date")
+    assert ex.match("value=bar, type=<class 'str'> is an invalid JWT expiration date, use `datetime.datetime` or `datetime.timedelta")
 
 
 def test_signer_unsign_expired_token():
@@ -77,7 +77,7 @@ def test_signer_unsign_expired_token():
         'location': 'JSON Web Token',
         'name': '_JWTError',
         'jwt_expiry': 1640995200,
-        'jwt_header': {u'alg': u'RS256', u'typ': u'JWT'},
+        'jwt_header': {'alg': 'RS256', 'typ': 'JWT'},
     }
 
 
@@ -117,8 +117,8 @@ def test_signer_unsign_invalid_payload(jwt_signer):
 
     assert value == {
         'location': 'JSON Web Token',
-        'jwt_header': {u'alg': u'RS256', u'typ': u'JWT'},
+        'jwt_header': {'alg': 'RS256', 'typ': 'JWT'},
         'description': 'No "data" attribute in payload/claims',
         'name': 'JwtSigner',
-        'jwt_payload': {u'foo': u'bar', u'exp': 2145916800},
+        'jwt_payload': {'foo': 'bar', 'exp': 2145916800},
     }
diff --git a/tests/util/test_numbers_common.py b/tests/util/test_numbers_common.py
index a6ebb516..1233a8e7 100644
--- a/tests/util/test_numbers_common.py
+++ b/tests/util/test_numbers_common.py
@@ -27,11 +27,11 @@ def generate(data):
 
 class TestNumberDecoding:
 
-    @pytest.mark.parametrize("number,expected,computed", generate(good), ids=good.keys())
+    @pytest.mark.parametrize("number,expected,computed", generate(good), ids=list(good.keys()))
     def testDecodeOK(self, number, expected, computed):
         self.check_ok(number, expected, computed)
 
-    @pytest.mark.parametrize("number,expected,computed", generate(bad), ids=bad.keys())
+    @pytest.mark.parametrize("number,expected,computed", generate(bad), ids=list(bad.keys()))
     def testDecodeBAD(self, number, expected, computed):
         self.check_ok(number, expected, computed)
 
diff --git a/tests/util/test_numbers_helper.py b/tests/util/test_numbers_helper.py
index 989ccaf7..c3ecb799 100644
--- a/tests/util/test_numbers_helper.py
+++ b/tests/util/test_numbers_helper.py
@@ -18,6 +18,6 @@ def test_read_numbersfile():
 
 """
     # TODO: Need to adjust for Python 3, see https://stackoverflow.com/a/34677735.
-    with patch("__builtin__.open", mock_open(read_data=data)) as mock_file:
+    with patch("builtins.open", mock_open(read_data=data)) as mock_file:
         numbers = read_numbersfile(None)
     assert numbers == ['EP666666', 'EP666667', 'EP666668', 'EP666669']
diff --git a/tests/util/test_numbers_normalize.py b/tests/util/test_numbers_normalize.py
index 6930587e..2fe9e69b 100644
--- a/tests/util/test_numbers_normalize.py
+++ b/tests/util/test_numbers_normalize.py
@@ -595,11 +595,11 @@ def normalize_patent_us_smart(input):
 
 class TestNumberNormalization:
 
-    @pytest.mark.parametrize("number,expected,computed", generate(t, fun=partial(normalize_patent, fix_kindcode=True, for_ops=True)), ids=t.keys())
+    @pytest.mark.parametrize("number,expected,computed", generate(t, fun=partial(normalize_patent, fix_kindcode=True, for_ops=True)), ids=list(t.keys()))
     def testDecodeOK(self, number, expected, computed):
         self.check_ok(number, expected, computed)
 
-    @pytest.mark.parametrize("number,expected,computed", generate(depatisconnect_cases, fun=partial(depatisconnect_alternatives)), ids=depatisconnect_cases.keys())
+    @pytest.mark.parametrize("number,expected,computed", generate(depatisconnect_cases, fun=partial(depatisconnect_alternatives)), ids=list(depatisconnect_cases.keys()))
     def test_depatisconnect_alternatives(self, number, expected, computed):
         self.check_ok(number, expected, computed)
 
diff --git a/tests/util/test_python.py b/tests/util/test_python.py
index ad8638a2..d3ce8955 100644
--- a/tests/util/test_python.py
+++ b/tests/util/test_python.py
@@ -8,11 +8,11 @@
 
 
 def test_run_command_success_basic():
-    assert run_command(["echo", "foo"]).read().strip() == "foo"
+    assert run_command(["echo", "foo"]).read().strip() == b"foo"
 
 
 def test_run_command_success_input():
-    assert run_command(["cat"], input="foo").read().strip() == "foo"
+    assert run_command(["cat"], input=b"foo").read().strip() == b"foo"
 
 
 def test_run_command_failure_not_found():
@@ -29,8 +29,8 @@ def test_run_command_failure_program_error():
 
 def test_run_command_failure_input_error():
     with pytest.raises(RuntimeError) as ex:
-        run_command(["true"], input={"abc": "def"})
-    assert ex.match('Command "true" failed, returncode=None, exception=unhashable type, stderr=')
+        run_command(["true"], input={b"abc": b"def"})
+    assert ex.match('Command "true" failed, returncode=None, exception=memoryview: a bytes-like object is required, not \'dict\', stderr=')
 
 
 def test_memoize():
@@ -49,4 +49,4 @@ def test_exception_traceback(capsys):
         output = exception_traceback()
 
     assert "Traceback (most recent call last)" in output
-    assert "NameError: global name 'foobar' is not defined" in output
+    assert "NameError: name \'foobar\' is not defined" in output
diff --git a/tests/util/test_text_format.py b/tests/util/test_text_format.py
index e0174517..a9680957 100644
--- a/tests/util/test_text_format.py
+++ b/tests/util/test_text_format.py
@@ -4,14 +4,14 @@
 
 
 def test_slugify():
-    assert slugify("Franz jagt Trueffel.") == "franz-jagt-trueffel"
-    assert slugify(u"Franz jagt Trüffel -=- im Wald. 👋") == "franz-jagt-truffel-im-wald"
-    assert slugify(u"Franz jagt Trüffel -=- im Wald. 👋", strip_equals=False) == "franz-jagt-truffel-=-im-wald"
-    assert slugify(u"Franz jagt Trüffel -=- im Wald. 👋", lowercase=False) == "Franz-jagt-Truffel-im-Wald"
+    assert slugify("Franz jagt Trueffel.") == b"franz-jagt-trueffel"
+    assert slugify("Franz jagt Trüffel -=- im Wald. 👋") == b"franz-jagt-truffel-im-wald"
+    assert slugify("Franz jagt Trüffel -=- im Wald. 👋", strip_equals=False) == b"franz-jagt-truffel-=-im-wald"
+    assert slugify("Franz jagt Trüffel -=- im Wald. 👋", lowercase=False) == b"Franz-jagt-Truffel-im-Wald"
 
 
 def test_text_indent():
-    assert text_indent(u"Franz jagt Trüffel.\nIm Wald.\n\n👋") == u"""
+    assert text_indent("Franz jagt Trüffel.\nIm Wald.\n\n👋") == """
     Franz jagt Trüffel.
     Im Wald.