[Python-Dev] decimal.py: == and != comparisons involving NaNs
Robert Kern
robert.kern at gmail.com
Mon Nov 9 05:20:35 CET 2009
Antoine Pitrou wrote:
> Stefan Krah <stefan-usenet <at> bytereef.org> writes:
>> Are there cases where == and != are actually needed to give a result
>> for NaNs?
>
> It is a common expectation that == and != always succeed. They return True or
> False, but don't raise an exception even on unrelated operands:
It is a common expectation, but a false one. __eq__ and __ne__ are explicitly
allowed to return anything, not just bools.
http://www.python.org/dev/peps/pep-0207/
--
Robert Kern
"I have come to believe that the whole world is an enigma, a harmless enigma
that is made terrible by our own mad attempt to interpret it as though it had
an underlying truth."
-- Umberto Eco
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