Wow -- thanks, guys. And who said Python only gives you one way to do things. :-) Metaclasses, globals(), and __subclasses__. Thank Duncan for the __subclassess__ tip -- I didn't know about that.
I'd totally overlooked globals(). It's exactly what I was looking for -- thanks, Peter. And I like your is_true_subclass() helper function too. I must say, I found it a bit weird that the first argument to issubclass() *has* to be a class. I would have thought issubclass(42, MyClass) would simply return False, because 42 is definitely not a subclass of MyClass. But I guess "explicit is better than implicit", and being implicit here might mask bugs. globals() feels like the "right" way to do what I want -- fairly simple and direct. Metaclasses are cool, but probably a touch too complicated for this. And __subclassess__ seems a bit undocumented and perhaps implementation-defined. Cheers, Ben. -- http://mail.python.org/mailman/listinfo/python-list
