[Python-Dev] Rich comparisons
Delaney, Timothy C (Timothy)
tdelaney at avaya.com
Sun Mar 21 17:18:21 EST 2004
> From: Edward Loper
>
> If we *really* want nan==nan to be false, then it seems like
> we have to
> say that nan is unhashable.
Hmm - I suppose we could make a subclass of float specifically for NaN, and have that be a singleton. The float constructor could check for a NaN result, and return this singleton.
I'm worried that there might be a slowdown though.
> I'm also disturbed by the fact
> that cmp()
> has something different to say about their equality:
>
> >>> cmp(float('nan'), float('nan'))
> 0
Hmm - I guess it should technically throw an exception. However, I'd be happy if it returned -1. Would this affect the stability of sorting?
Tim Delaney
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