Message365742
In section "6.10.1 Value comparisons", it is written:
https://docs.python.org/3/reference/expressions.html
"The not-a-number values float('NaN') and decimal.Decimal('NaN') are
special. Any ordered comparison of a number to a not-a-number value is
false. A counter-intuitive implication is that not-a-number values are
not equal to themselves. For example, if x = float('NaN'), 3 < x, x <
3, x == x, x != x are all false. This behavior is compliant with IEEE
754."
Last comparison "x != x" does not return False, it returns True. Here is the output from my iPython interpeter I am using on Arch Linux (latest as of today):
In [86]: x == y
Out[86]: False
In [87]: x != y
Out[87]: True
I verified the bug it on Wikipedia too:
https://en.wikipedia.org/wiki/NaN#Comparison_with_NaN |
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Date |
User |
Action |
Args |
2020-04-04 03:36:05 | ArnuldOnData | set | recipients:
+ ArnuldOnData, docs@python |
2020-04-04 03:36:05 | ArnuldOnData | set | messageid: <1585971365.58.0.193657354587.issue40177@roundup.psfhosted.org> |
2020-04-04 03:36:05 | ArnuldOnData | link | issue40177 messages |
2020-04-04 03:36:05 | ArnuldOnData | create | |
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