added abstract class to select appropriate Cython classes

graphi/types/cython_graph/__init__.py

@@ -0,0 +1,19 @@
+from ...abc import Graph as GraphABC
+from ..decorator import boundable, undirectable
+
+from .plain_graph import CythonGraph as _PlainGraph
+
+
+@boundable
+@undirectable
+class CythonGraph(GraphABC):
+    """
+    Optimised Cython Graph Implementations
+
+    .. note:: This is an abstract class that merely picks the most suitable implementation.
+    """
+    def __new__(cls, *args, **kwargs):
+        return _PlainGraph(*args, **kwargs)
+
+
+CythonGraph.register(_PlainGraph)

graphi_unittests/types_unittests/test_cython_graph/test_plain_graph.py

@@ -18,5 +18,5 @@ def __new__(cls, *args, **kwargs):
 
 
 @unittest.skipIf(platform.python_implementation() != 'CPython', 'Cython extension not available outside of CPython')
-class TestCythonGraphInterface(mixins.Mixin.GraphInitMixin, mixins.Mixin.GraphInterfaceMixin):
+class TestCythonPlainGraphInterface(mixins.Mixin.GraphInitMixin, mixins.Mixin.GraphInterfaceMixin):
     graph_cls = CythonGraph

graphi_unittests/types_unittests/test_cython_graph/test_public_graph.py

@@ -0,0 +1,22 @@
+import platform
+try:
+    import unittest2 as unittest
+except ImportError:
+    import unittest
+
+try:
+    from graphi.types.cython_graph import CythonGraph
+except ImportError as err:
+    class CythonGraph(object):
+        failure_reason = str(err)
+
+        def __new__(cls, *args, **kwargs):
+            raise ImportError(cls.failure_reason)
+    del err
+
+from graphi_unittests.types_unittests import _graph_interface_mixins as mixins
+
+
+@unittest.skipIf(platform.python_implementation() != 'CPython', 'Cython extension not available outside of CPython')
+class TestCythonGraphInterface(mixins.Mixin.GraphInitMixin, mixins.Mixin.GraphInterfaceMixin):
+    graph_cls = CythonGraph