Why can't I xor strings?

[Alex Martelli]

Bernhard Herzog <bh at intevation.de> wrote:
   ...
> >     not str1 ^ not str2
> >     not str1 != not str2
> 
> These give syntax errors, actually.  I wouldn't have expected that
> either, though :)

Yep, you need parentheses, as in (not str1) &c.

> >     str1 != str2 and (str1+str2) == (str2+str1)
> 
> Counter example:
> >>> str1 = "x"; str2 = "xx"

Yep, excellent counterexample, thanks.  So let's try instead:

  (str1+str2==str2!=str1) or (str2+str1==str1!=str2)

I _do_ really want something based on concatenation equaling one of the
strings iff the other's empty...


Alex