michael@0: import sys
michael@0: 
michael@0: info = sys.version_info
michael@0: if info[:3] >= (3, 2, 0):
michael@0:     # for Python 3.2 ordinary unittest is fine
michael@0:     import unittest as unittest2
michael@0: else:
michael@0:     import unittest2
michael@0: 
michael@0: 
michael@0: try:
michael@0:     callable = callable
michael@0: except NameError:
michael@0:     def callable(obj):
michael@0:         return hasattr(obj, '__call__')
michael@0: 
michael@0: 
michael@0: inPy3k = sys.version_info[0] == 3
michael@0: with_available = sys.version_info[:2] >= (2, 5)
michael@0: 
michael@0: 
michael@0: def is_instance(obj, klass):
michael@0:     """Version of is_instance that doesn't access __class__"""
michael@0:     return issubclass(type(obj), klass)
michael@0: 
michael@0: 
michael@0: class SomeClass(object):
michael@0:     class_attribute = None
michael@0: 
michael@0:     def wibble(self):
michael@0:         pass
michael@0: 
michael@0: 
michael@0: class X(object):
michael@0:     pass
michael@0: 
michael@0: try:
michael@0:     next = next
michael@0: except NameError:
michael@0:     def next(obj):
michael@0:         return obj.next()