[Python-Dev] 2.1.1 maintenance branch (original) (raw)

Neil Schemenauer nas@python.ca
Thu, 18 Oct 2001 12:53:22 -0700

Guido van Rossum wrote:

I'n curious about abstractisinstance -- is that what you checked in last night?

Yes.

I thought that was for 2.2 but I may have misunderstood the issue (I have to admit I have no idea what abstractisinstance does any more :-( ).

No, abstract_isinstance has been broken for a long time, maybe forever. It is supposed to work for class-like objects like ExtensionClass instances as well as for standard classes and types. One problem was that if you gave it a normal instance as the first argument but an ExtensionClass as the second argument it raised a type error. It's annoying to us at the MEMS Exchange because we use ExtensionClasses and isinstance all the time (Greg likes type checking). We ended up rewriting isinstance() and issubclass() in Python. The average Python user doesn't care.

Neil