On 5/10/06, Bill Birch <[EMAIL PROTECTED]> wrote: > A simple test to see where your thinking is at. Consider: [...] > The manual for isinstance() says: "return true if classinfo is a type object > and object is an object of that type". So consider this: > > isinstance( D(), I1 ) > > Is this True or False?
(Making obvious assumptions about the syntax that isn't "real" Python...) Clearly False - D() is not an object of type I1. Of course, whether isinstance() is actually a useful way of checking depends on what you're trying to discover. It's very rare that I'd care about the actual class inheritance structure of an object. What I care about is whether I can *use* it like an I1. And that's not decidable (it includes semantic considerations), so no builtin can answer that question for me. Hence, I document my expectations, and trust my caller to follow the documentation. We're all consenting adults, and all that... (Note: This is ideal documentation, not real-life, you understand :-)) So where does that put my thinking? Paul. _______________________________________________ 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
