Re: any() and all() on empty list?

Ron Adam wrote:
> Carl Banks wrote:
>
> > In Python, yes and no are the only possible answers. Probably the only
> > analogous thing you could do in Python would be for all() to raise
> > ValueError when passed an empty sequence.
>
> There is also 'None' which serves a similar purpose of indicating an
> invalid value when passing arguments.

If all() were to return None, then if would essentially be like
returning False, because an if-statement would treat False and None the
same (as would most anything else expecting a boolean value).

The only reasonable way to say "false assumption" in Python is to raise
an exception.

Carl Banks
Received on Sun Apr 30 21:48:22 2006