Why return None?

[Dan Bishop]

Dave Opstad <dave.opstad at agfamonotype.com> wrote in message news:<dave.opstad-E72D18.07305325082004 at reader0903.news.uu.net>...
>
> [discussion of why list.sort returns None instead of a list]
>
> But isn't the fact that the list is modified in place incidental to the 
> fact of sorting? One is an implementation detail, and the other is the 
> semantic meaning you're trying to express.

The fact that the list is sorted in-place *is* semantically
meaningful.  It's often important to know whether the original list is
sorted or not.