On 26.08.2021 10:02, Peter Otten wrote:
> On 26/08/2021 09:36, Marc-Andre Lemburg wrote:
>
>> In Python you can use a simple test for this:
>
> I think you need math.isnan().
>
>>>>> nan = float('nan')
>>>>> l = [1,2,3,nan]
>>>>> d = {nan:1, 2:3, 4:5, 5:nan}
>>>>> s = set(l)
>>>>> nan in l
>> True
>
> That only works with identical nan-s, and because the container omits the
> equality check for identical objects:
>
>>>> nan = float("nan")
>>>> nan in [nan]
> True
>
> But:
>
>>>> nan == nan
> False
>>>> nan in [float("nan")]
> False
Oh, good point. I was under the impression that NAN is handled
as a singleton.
Perhaps this should be changed to make to make it easier to
detect NANs ?!
--
Marc-Andre Lemburg
eGenix.com
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