float("nan") in set or as key

[Wolfgang Rohdewald]

On Sonntag 29 Mai 2011, Tim Delaney wrote:
> There's a second part the mystery - sets and dictionaries (and
> I think lists) assume that identify implies equality (hence
> the second result). This was recently discussed on
> python-dev, and the decision was to leave things as-is.

On Sonntag 29 Mai 2011, Grant Edwards wrote:
> Even if they are the same nan, it's still not equal to itself.

if I understand this thread correctly, they are not equal to
itself as specified by IEEE but Python treats them equal in
sets and dictionaries for performance reasons

-- 
Wolfgang