[Python-Dev] Why is nan != nan? (original) (raw)

Guido van Rossum guido at python.org
Fri Mar 26 00:14:30 CET 2010


On Thu, Mar 25, 2010 at 12:31 PM, Glenn Linderman <v+python at g.nevcal.com> wrote:

It is my understand that even bit-for-bit identical NaN values will compare unequal according to IEEE 754 rules.

I would have no problem with Python interning each encountered NaN value, to avoid having bit-for-bit identical NaN values with different Python IDs, but having them compare equal seems inappropriate.

Let's please not intern NaNs. Interning is for performance. If you have enough NaNs to affect your performance I think you have bigger worries!

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



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