python extras

.travis.yml

@@ -3,6 +3,15 @@ python:
 - '2.7'
 install:
 - make compile
+
 script:
 - make test
-- make publish
+
+publish:
+	make publish
+
+stages:
+  - compile
+  - test
+  - publish
+    if: branch = master

extras/__init__.py

@@ -0,0 +1,52 @@
+"""
+  python package "extras" module
+
+  *Attempt* to import a library, without knowing if it's installed.
+  May optionally throw an error
+
+
+"""
+import inspect
+import logging
+
+logger = logging.getLogger(__name__)
+
+MODULES={}
+
+
+def __getitem__(module_name):
+    """ hash interface with extras, throw error if 
+    module doesn't exist.
+    """
+    module = MODULES.get(module_name)
+
+    if module:
+        return module
+
+    module = __import__(module_name)  
+    MODULES[module_name] = module
+
+    return module
+
+
+def get(module_name):
+    """ return package if package exists, None if fails.
+        should cache imported modules
+    """
+
+    try:
+        return __getitem__(module_name)
+
+    except ImportError as err:
+        logger.info("Excluding `%s` because it's not installed."%module_name)
+
+
+def not_important(module_name):
+    """ `import` directly to the class binding.
+    reference the class just like you used `import`.
+    `module_name is None` checks for existance.
+    """
+    stack = inspect.stack()
+    klass = stack[1][0].f_locals[module_name] = get(module_name)
+
+optional = not_important

tests/unit/extras/getter_test.py

@@ -0,0 +1,23 @@
+from pytest import raises, mark
+import extras
+
+class TestExtrasGetters:
+    def test_get_module(self):
+        numpy = extras.get('numpy')
+        # assert type(numpy.array([1,2,3,4,5])) == numpy.array
+        arr = numpy.array([0,1,2,3,4,5]) 
+
+        assert arr[0] == 0
+
+
+    def test_get_non_existing_module(self):
+        nopy = extras.get('nopy')
+
+        assert nopy is None
+
+
+    @mark.skip("nice to have, jacking module")
+    def test_brackets(self):
+        numpy = extras['numpy']
+        assert isinstance(numpy.array([1,2,3,4,5]), numpy.array)
+

tests/unit/extras/optional_import_test.py

@@ -0,0 +1,15 @@
+from pytest import raises
+from extras import not_important
+not_important('numpy')
+not_important('garbage')
+
+
+class TestExtrasGetters:
+    def test_import_module(self):
+        arr = numpy.array([0,1,2,3,4,5]) 
+
+        assert arr[0] == 0
+
+
+    def test_non_existing_module(self):
+        assert garbage is None