add global module for python compatibility

src/martian/compat.py

@@ -0,0 +1,7 @@
+import types
+
+
+if hasattr(types, 'ClassType'):
+    CLASS_TYPES = (type, types.ClassType)
+else:
+    CLASS_TYPES = (type,)

src/martian/core.py

@@ -8,6 +8,7 @@
                                 GlobalGrokker)
 from martian.error import GrokError
 from martian.martiandirective import component, priority
+from martian.compat import CLASS_TYPES
 
 @implementer(IMultiGrokker)
 class MultiGrokkerBase(GrokkerBase):
@@ -180,9 +181,7 @@ def clear(self):
         self._multi_global_grokker = MultiGlobalGrokker()
 
     def grokkers(self, name, obj):
-    # python3 compatible
-        if isinstance(obj, type) or (hasattr(types, 'ClassType')
-                                     and isinstance(obj, types.ClassType)):
+        if isinstance(obj, CLASS_TYPES):
             return self._multi_class_grokker.grokkers(name, obj)
         elif isinstance(obj, types.ModuleType):
             return self._multi_global_grokker.grokkers(name, obj)

src/martian/util.py

@@ -22,6 +22,7 @@
 from zope import interface
 
 import martian
+from martian.compat import CLASS_TYPES
 from martian.error import GrokError, GrokImportError
 
 def not_unicode_or_ascii(value):
@@ -44,9 +45,7 @@ def not_unicode_or_ascii(value):
 def isclass(obj):
     """We cannot use ``inspect.isclass`` because it will return True
     for interfaces"""
-    # python3 compatible
-    return isinstance(obj, type) or (hasattr(types, 'ClassType') and
-                                     isinstance(obj, types.ClassType))
+    return isinstance(obj, CLASS_TYPES)
 
 
 def check_subclass(obj, class_):