On Tue, May 24, 2016 at 3:09 AM, Jon Ribbens <jon+use...@unequivocal.co.uk> wrote: > On 2016-05-23, Steven D'Aprano <st...@pearwood.info> wrote: >> But one thing is certain: very few people, Jon Ribbens being one of them, >> expects 1/3 to return 0. And that is why Python changed the meaning of >> the / operator: because using it for integer division was deeply unpopular >> and a bug magnet. > > Making it return floats is also a bug magnet, just for more subtle > bugs that are harder to diagnose.
See my earlier post. There are four broadly-viable options: int, float, Fraction, Decimal. *Every one of them* is a bug magnet in one way or another. Which kind of bug would you like? * 1235678678/3 == 411892892 * (1/3) + (1/3) + (1/3) != 1 * x != x + 0 * useless reprs after a few rounds of addition Take your pick. :) By the way, did you know that Python has support for fraction literals? Just put this at the top of your code: import fractions; f = fractions.Fraction(1) and then you can use the special "tagged literal" syntax, like with special forms of string literal: >>> f*22/7 + f*2/11 Fraction(256, 77) There's even a short-hand form for the common case where the numerator is 1: >>> f/2 + f/3 Fraction(5, 6) Very handy, particularly interactively. :) ChrisA -- https://mail.python.org/mailman/listinfo/python-list
