Check that keywords attribute is not None, important for Python < 2.7.10. Fixes
@@ -82,6 +82,7 @@ if sys.version_info[:2] < (3, 4):
elif isinstance(func, partial):
sig = getargspec(func.func)
if 'self' in sig.args: sig.args.remove('self')
+ if func.keywords is not None:
for name in func.keywords.keys():
sig.args.remove(name)
for val in func.args:
