Re: test for nan

From: Peter Maas (fpetermaas_at_netscape.net)
Date: 04/01/04 

Date: Thu, 01 Apr 2004 10:23:41 +0200

John Hunter wrote:
> I have a C extension module that is returning some doubles. When the
> doubles get out of range, the numbers print as 'nan'.
>
> Is there a better way to test for NaN than
>
> str(p1)=='nan'
>
> where p1 is a float?
>
> python2.3
>
> Thanks,
> John Hunter
>

As far as I know NaN is th only value that yields false when compared
to itself. This leads to

def isNaN(x):
     return (x == x) == False

Mit freundlichen Gruessen,

Peter Maas 

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