Why can't I xor strings?

[Paul Rubin]

dataangel <k04jg02 at kzoo.edu> writes:
> To save time the first thing my function does is check if
> I'm comparing an empty vs. a non-empty string, because they are to be
> never considered similar.

> Right now I have to write out the check like this:
> 
>     if str1 and str2:
>         if not str1 or not str2:
>             return 0

How about:

    def nonempty(s):
        return (len(s) > 0) 

and then

    if nonempty(str1) != nonempty(str2):
       return 0

Of course there's other ways to write the same thing.  Python 2.3 has
a "bool" function which when called on a string, returns true iff the
string is nonempty.