On Wed, 15 Jul 2009 11:51:44 -0700 (PDT), Mark Dickinson <dicki...@gmail.com> wrote:
>On Jul 15, 7:29 pm, Wayne Brehaut <wbreh...@mcsnet.ca> wrote: >> On Tue, 14 Jul 2009 11:47:41 -0700 (PDT), Mark Dickinson >> <dicki...@gmail.com> wrote: >> >I'd also guess that 'xor' would be much less used than 'and' or 'or', >> >but maybe that's just a reflection of the sort of code that I tend to >> >write. >> >> You're right about that!. It's used everywhere in: >> [snip examples and references] > >Those examples are (almost) all about the *bitwise* xor operator, >which exists in Python ('^') and, as you point out, has no shortage of >good uses. The discussion was about a *logical* xor, to parallel the >existing 'and' and 'or' operators. I thought you were saying your program domains didn't include a lot of requirements for xor in general, rather than just no uses for Boolean xor--and I'm used to thinking of xor on binary vectors as "Boolean" anyway so would still have been confused. The most common non-binary-bit-wise xor is the general "symmetric difference" of sets, most likely to be useful in list or dictionary processing or database-like contexts. Please see my suggested use-case for Steven below. wayne -- http://mail.python.org/mailman/listinfo/python-list