[Python-ideas] math.inf and math.nan constants

[Guido van Rossum]

On Mon, Jan 12, 2015 at 8:54 AM, Chris Barker <chris.barker at noaa.gov> wrote:
>
> Being able to do x is math.nan, and have that give the answer most
> commonly wanted would be a nice way to spell, but, again, not worth
> breaking the now clear definition of "is".
>

While this discussion about what the meaning of "is" is is a funny in-joke
for those who remember the Clinton impeachment trials, that you even
considered it (and posted about it!) makes me shudder -- Python's "is"
operator is so closely tied to object identity that to propose overriding
it as a kind of "category" test makes me wonder if you understand Python at
all. Proposing to change "==" to make all NaNs appear equal would be less
earth-shattering -- that might go against all IEEE fp standards, but at
least Python's "==" operator is intended for that purpose.

-- 
--Guido van Rossum (python.org/~guido)
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