On Jan 24, 2008 3:32 PM, Michael Foord <[EMAIL PROTECTED]> wrote: > > Jeffrey Yasskin wrote: > > On Jan 24, 2008 1:11 PM, Raymond Hettinger <[EMAIL PROTECTED]> wrote: > > > >> [Raymond Hettinger] > >> > >>> Since something similar is happening to math.ceil and math.floor, > >>> I'm curious why trunc() ended-up in builtins instead of the math > >>> module. Doesn't it make sense to collect similar functions > >>> with similar signatures in the same place? > >>> > >> [Christian Heimes] > >> > >>> Traditionally the math module is a tiny wrapper around the > >>> system's libm. Functions for magic hooks like __trunc__ > >>> usually end up in builtins. In this particular case I don't > >>> mind where the function is going to live. > >>> > >> Traditions have gone out the window. ceil() and floor() > >> are going to have their signatures changed (Real --> Integral) > >> and are going to have their own magic methods. They cannot > >> be characterized as a thin wrapper around libm. > >> > >> So the question stands, why is trunc() different? Can anything > >> good come from having trunc() and int() in the same namespace? > >> > > > > One of my goals for trunc() is to replace the from-float use of int(), > > even though we can't remove it for backward-compatibility reasons. PEP > > 3141 says: > > > > "Because the int() conversion implemented by float (and by > > decimal.Decimal) is equivalent to but less explicit than trunc(), > > let's remove it. (Or, if that breaks too much, just add a deprecation > > warning.)" > > > > That needs to be updated and implemented. I think the decision was > > that removing float.__int__() would break too much, so it needs a > > deprecation warning in 3.0. > > > > int has to be a builtin because it's a fundamental type. trunc() > > followed round() into the builtins. I have no opinion on whether ceil > > and floor should move there; it probably depends on how often they're > > used. > > > > > So you won't be able to construct an int from a float? That sucks (and > is unintuitive).
Yes, you can, but you have to specify how you want it done by using trunc() or round() or ceil() or floor(). (In 3.0, round(x) will return an int, not a float.) -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ 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
