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

Greg Ewing greg.ewing at canterbury.ac.nz
Mon Mar 29 01:55:55 CEST 2010


Steven D'Aprano wrote:

I disagree -- if I ask:

3.0 in [1.0, 2.0, float('nan'), 3.0] I should get True, not an exception.

Yes, I don't think anyone would disagree that NaN should compare unequal to anything that isn't a NaN. Problems only arise when comparing two NaNs.

-- Greg



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