Gabriel Genellina wrote: > En Fri, 13 Feb 2009 08:07:58 -0200, Carl Banks <pavlovevide...@gmail.com> > escribió: > >> Well, the OP said he was using Python 3.0, where all classes are new- >> style classes. >> >> But that brings up another very slight possibility, though not a very >> likely one in this case: the behavior of isinstance can be >> customized. It can happen unbeknownst to a user who subclasses a >> class that does that. > > Really? I didn't know that -- how do you do that? >>> class Type(type): ... def __instancecheck__(self, other): return True ... >>> class A(metaclass=Type): pass ... >>> class B: pass ... >>> isinstance(B(), A) True
See also http://www.python.org/dev/peps/pep-3119/#overloading-isinstance-and-issubclass I doubt that this is the source of the OP's troubles, though. Peter -- http://mail.python.org/mailman/listinfo/python-list