Re: [Python-ideas] Why is nan != nan?

On Sat, Mar 27, 2010 at 10:21 AM, Marcin 'Qrczak' Kowalczyk wrote:

The original problem with NaN is a consequence of an unfortunate decision to unify numeric equality with object equivalence. If they were distinguished, their behavior would be obvious:

Agreed, except that it's not clear to me that this was actually an unfortunate decision. The results in this context are unfortunate, yes, but it could well be that distinguishing numeric equality and object equivalence would add unacceptable complexity to the language for those trying to learn it. Questions about 'is' versus '==' are especially common on the mailing lists, and adding a third equivalence relation wouldn't help newcomers. Mark