Jordan Greenberg <[EMAIL PROTECTED]> wrote: > Guido van Rossum wrote: > > How would this change be helpful? I'm utterly mystified by these > > suggestions that bool would be more useful if it didn't behave like an > > int in arithmetic. > > I don't think anyones really saying it would be more useful, it > obviously wouldn't, since like Greg said, it wouldn't work in mapping > access or set membership like it does now. I think it would be more > readable though, since thinks like this: > >>> True in set([1]) > True > > or that 5+True is equal to 6 aren't necessarily obvious to someone who > doesn't know that True evaluates to 1.
Maybe, but 30-some years of C semantics and another 15 years of Python semantics die hard. a==b for builtin types used to return 1 or 0, now they return True or False. Changing such semantics because some users haven't ever used C or older Pythons would be a bit like changing 'def' to 'fcn' because some users have never used 'def' to define a function. Learn the semantic and move on. > It is elegant to embed bool in int, but to me it screams C. To me, it > makes more sense to use an int if you want an int, and to reserve > boolean for logic. You say "screams C" as if it were necessarily a bad thing. Certainly C isn't a perfect language (which is why I use Python), but there are many reasons why I (and others) use (or not) C, but I can just about guarantee you that the semantics of booleans in C *help* rather than hurt its adoption. > From an elegance/usefulness standpoint, maybe bool should evaluate to 0 > and 1. But IMHO, it would eliminate some gotchas and improve readability > if it didn't. You are, of course, entitled to your opinion. From what I understand, there is perhaps one major "gotcha" in the current semantics: bool(str(<obj>)) isn't correct for anything except for '' and u''. Then again, that isn't a guarantee with str or bool (or list, tuple, dict, deque, set, etc.) - Josiah _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
