[Python-Dev] Should issubclass() be more like isinstance()?

Crutcher Dunnavant crutcher at gmail.com
Wed Apr 5 02:55:32 CEST 2006


On 4/4/06, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
> Crutcher Dunnavant wrote:
>
> > A) issubclass() throws a TypeError if the object being checked is not
> > a class, which seems very strange.
>
> If I ever pass a non-class to issubclass() it's almost
> certainly a bug in my code, and I'd want to know about
> it.

Perhaps, but is it worth distorting a predicate?

> On the rare occasions when I don't want this, I'm
> happy to write
>
>    isinstance(c, type) and issubclass(c, d)

This doesn't work, did you mean?
  isinstance(c, types.ClassType) and issubclass(c, d)


> > B) issubclass() won't work on a list of classs,
>  > the way isinstance() does.
>
> That sounds more reasonable. I can't think of any
> reason why it shouldn't work.
>
> --
> Greg
>


--
Crutcher Dunnavant <crutcher at gmail.com>
littlelanguages.com
monket.samedi-studios.com


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