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

Guido van Rossum guido@python.org
Thu, 18 Oct 2001 15:58:20 -0400

> 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, abstractisinstance 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.

Then I'm not sure if this should be fixed in 2.1.2. It's almost a new feature that it doesn't bomb out. :-(

--Guido van Rossum (home page: http://www.python.org/~guido/)