New submission from Jeffrey Yasskin: Python 2.6a0 (trunk:59791M, Jan 6 2008, 12:22:37) [GCC 4.0.1 (Apple Computer, Inc. build 5367)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> import abc [30620 refs] >>> class A: ... __metaclass__ = abc.ABCMeta ... [30650 refs] >>> class B: ... pass ... [30659 refs] >>> issubclass(B, A) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/Users/jyasskin/src/python/trunk-abc/Lib/abc.py", line 191, in __subclasscheck__ if cls in subclass.__mro__: AttributeError: class B has no attribute '__mro__' [30701 refs] >>>
This causes Decimal to break in interesting ways when I make it subclass numbers.Real. test_abc doesn't catch it because it declares __metaclass__=type at the top level. :-( This looks relatively easy to fix, so I'll work on a patch. ---------- assignee: jyasskin components: Library (Lib) messages: 59412 nosy: gvanrossum, jyasskin severity: normal status: open title: isinstance(NotSubclassOfObject, InstanceOfAbcMeta) fails instead of returning False versions: Python 2.6 __________________________________ Tracker <[EMAIL PROTECTED]> <http://bugs.python.org/issue1747> __________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com