On Sat, Nov 20, 2021 at 5:08 AM ast <ast@invalid> wrote: > > Le 19/11/2021 à 03:51, MRAB a écrit : > > On 2021-11-19 02:40, 2qdxy4rzwzuui...@potatochowder.com wrote: > >> On 2021-11-18 at 23:16:32 -0300, > >> René Silva Valdés <rene.silva.val...@gmail.com> wrote: > >> > >>> Hello, I would like to report the following issue: > >>> > >>> Working with floats i noticed that: > >>> > >>> int(23.99999999999999/12) returns 1, and > >>> int(23.999999999999999/12) returns 2 > >>> > >>> This implies that int() function is rounding ... > >> > >> It's not int() that's doing the rounding; that second numerator is being > >> rounded before being divided by 12: > >> > >> Python 3.9.7 (default, Oct 10 2021, 15:13:22) > >> [GCC 11.1.0] on linux > >> Type "help", "copyright", "credits" or "license" for more > >> information. > >> >>> 23.999999999999999 > >> 24.0 > >> >>> (23.999999999999999).hex() > >> '0x1.8000000000000p+4' > >> > > I think this is a bit clearer because it shows that it's not just being > > rounded for display: > > > > Python 3.10.0 (tags/v3.10.0:b494f59, Oct 4 2021, 19:00:18) [MSC v.1929 > > 64 bit (AMD64)] on win32 > > Type "help", "copyright", "credits" or "license" for more information. > > >>> 23.99999999999999 == 24 > > False > > >>> 23.999999999999999 == 24 > > True > > >>> 0.3 + 0.3 + 0.3 == 0.9 > False
That's because 0.3 is not 3/10. It's not because floats are "unreliable" or "inaccurate". It's because the ones you're entering are not what you think they are. When will people understand this? (Probably never. Sigh.) ChrisA -- https://mail.python.org/mailman/listinfo/python-list
