On 4/28/07, Calvin Spealman <[EMAIL PROTECTED]> wrote: > I'm just going to jump into this and voice a concern that allowing > overriding of isinstance and issubclass seems like a Bad Idea.
I'm also uncomfortable, which is why I originally suggested a parallel predicate. That said, I can't put my finger on why it is wrong, so I'm not certain that a parallel predicate (isa?) would be better. Guido wrote: > Note though that only the second argument to either function can > overload the rules. IOW if you write isinstance(x, C), there is no way > that x could attempt to lie; but C could. As Barry pointed out, this means a class can't easily say "my parent may well implement ABC, but I don't." That special case could be added to the default overriding behavior, but ... it starts to get fragile. -jJ _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
