initial support for 429 TooManyRequests HTTP code

SPARQLWrapper/SPARQLExceptions.py

@@ -84,3 +84,16 @@ class URITooLong(SPARQLWrapperException):
 
     msg = "the URI requested by the client is longer than the server is willing to interpret. Check if the request was sent using GET method instead of POST method."
 
+class TooManyRequests(SPARQLWrapperException):
+    """
+    The user has sent too many requests in a given amount of time ("rate limiting"). Usually HTTP response status code 429.
+    @since: 1.8.5
+    """
+
+    def __init__(self, response=None, retry_after=None):
+        self.msg = "The user has sent too many requests in a given amount of time ('rate limiting'). Retry-After header (if present) indicates how long to wait before making a new request (possible values are <http-date> and <delay-seconds>)."
+        if retry_after:
+            self.msg += "Retry-After header value="+retry_after
+
+        super(TooManyRequests, self).__init__(response)
+        self.retry_after = retry_after

SPARQLWrapper/Wrapper.py

@@ -32,7 +32,7 @@
 
 import json
 from .KeyCaseInsensitiveDict import KeyCaseInsensitiveDict
-from .SPARQLExceptions import QueryBadFormed, EndPointNotFound, EndPointInternalError, Unauthorized, URITooLong
+from .SPARQLExceptions import QueryBadFormed, EndPointNotFound, EndPointInternalError, Unauthorized, URITooLong, TooManyRequests
 from SPARQLWrapper import __agent__
 
 # alias
@@ -743,8 +743,9 @@ def _query(self):
         :raises Unauthorized: If the HTTP return code is ``401``.
         :raises EndPointNotFound: If the HTTP return code is ``404``.
         :raises URITooLong: If the HTTP return code is ``414``.
+        :raises TooManyRequests: If the HTTP return code is ``429``.
         :raises EndPointInternalError: If the HTTP return code is ``500``.
-        :raises urllib2.HTTPError: If the HTTP return code is different to ``400``, ``401``, ``404``, ``414``, ``500``.
+        :raises urllib2.HTTPError: If the HTTP return code is different to ``400``, ``401``, ``404``, ``414``, ``429``, ``500``.
         """
         request = self._createRequest()
 
@@ -763,6 +764,12 @@ def _query(self):
                 raise Unauthorized(e.read())
             elif e.code == 414:
                 raise URITooLong(e.read())
+            elif e.code == 429:
+                hdrs = KeyCaseInsensitiveDict(e.headers) # Case insensitive headers
+                if "retry-after" in hdrs:
+                    raise TooManyRequests(e.read(), hdrs["retry-after"])
+                else:
+                    raise TooManyRequests(e.read())
             elif e.code == 500:
                 raise EndPointInternalError(e.read())
             else:

test/wrapper_test.py

@@ -37,7 +37,7 @@
 from SPARQLWrapper import XML, GET, POST, JSON, JSONLD, N3, TURTLE, RDF, SELECT, INSERT, RDFXML, CSV, TSV
 from SPARQLWrapper import URLENCODED, POSTDIRECTLY
 from SPARQLWrapper import BASIC, DIGEST
-from SPARQLWrapper.Wrapper import QueryResult, QueryBadFormed, EndPointNotFound, EndPointInternalError, Unauthorized, URITooLong
+from SPARQLWrapper.Wrapper import QueryResult, QueryBadFormed, EndPointNotFound, EndPointInternalError, Unauthorized, URITooLong, TooManyRequests
 
 
 class FakeResult(object):
@@ -49,13 +49,12 @@ def urlopener(request):
     return FakeResult(request)
 
 
-def urlopener_error_generator(code):
+def urlopener_error_generator(code, headers={}):
     def urlopener_error(request):
-        raise HTTPError(request.get_full_url, code, '', {}, StringIO(''))
+        raise HTTPError(request.get_full_url, code, '', headers, StringIO(''))
 
     return urlopener_error
 
-
 def urlopener_check_data_encoding(request):
     if isinstance(request.data, str):
         raise TypeError
@@ -515,6 +514,18 @@ def testQuery(self):
         except:
             self.fail('got wrong exception')
 
+        RETRY_AFTER_VALUE = "100"
+        _victim.urlopener = urlopener_error_generator(429, {"Retry-After": RETRY_AFTER_VALUE})
+        try:
+            self.wrapper.query()
+            self.fail('should have raised exception')
+        except TooManyRequests as e:
+            #  TODO: check exception-format
+            self.assertEquals(e.retry_after, RETRY_AFTER_VALUE)
+            pass
+        except:
+            self.fail('got wrong exception')
+
         _victim.urlopener = urlopener_error_generator(500)
         try:
             self.wrapper.query()