STINNER Victor added the comment: 2015-01-09 8:16 GMT+01:00 Serhiy Storchaka <rep...@bugs.python.org>: > May be make math.inf and math.nan special objects so that for all x (except > inf and nan):
What do you mean? Implement a subtype of float and override some methods? > x < math.inf > x > -math.inf It's already the case for int, float and decimal.Decimal. > not (x < math.nan) > not (x > math.nan) Comparison to nan always return False. I would be better to raise an error when nan is compared to other numbers (I mean operations like a>b, not a==b), but Python was not designed like that (nor the IEEE 754?). >>> sorted((nan, 1, nan, 2)) [nan, 1, nan, 2] Sorting with NaN is a common issue :-/ See for example: https://stackoverflow.com/questions/4240050/python-sort-function-breaks-in-the-presence-of-nan Anyway, changing NaN behaviour is out of the scope of this issue! ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue23185> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
