On Tue, Nov 11, 2008 at 10:20 AM, Tim Peters <[EMAIL PROTECTED]> wrote: > [M.-A. Lemburg] >> ... >> That's fine. I'm just talking about the special case for None that >> has existed in Python for years - and for a good reason. > > That's overstating it a bit ;-) In Python 1.5.1, comparisons were > changed so that objects of numeric types compared smaller than objects > of non-numeric types, and then 0 < None was true, not None < 0 (which > became true substantially later). The reason for that change is > explained in Misc/HISTORY (it was an attempt to preserve transitivity > across chains of mixed-type comparisons). > > Later, during the move to rich comparisons, I was hacking the code in > the same room with Guido, and realized something special had to be > done with None. > > "Hey, Guido, what should we do about mixed-type comparisons against None?" > > "Hmm ... what do you think?" > > "Hmm ... OK, let's make None smaller than other types." > > "Why?" > > "Oh, why not?" > > "Good enough -- but let's not document it -- it's an arbitrary > implementation detail." > > "Of course!" > > In any case, we thought this was so arbitrary that we didn't hesitate > to break that, up until that time, "0 < None" /had/ been true "for > years - and for a good reason" ;-) > > not-all-good-reasons-are-particularly-good-ly y'rs - tim
Hah! I can vouch that this is pretty much how it went. It's a good thing our process has changed a bit; in today's world this would have required a PEP, and for good reason. I would have fought the proposal if it had been proposed as a new feature for Python 3000. welcome-back-tim-ly y'rs, -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
