En Sat, 31 Jan 2009 11:03:13 -0200, andrew cooke <and...@acooke.org>
escribió:
Just a correction: according to the doc, NotImplemented is not an
error, but a returned value.
curious, so it is. i wonder why there is both a special return value
(NotIMplemented) and a related exception (NotImplementedError). seems
very odd to have a value...
I consider it an optimization. Raising an exception is more costly than
returning a value, and this failure is likely to happen often (not all
types define all possible operators). AFAIK this is only recognized by the
binary operators (__add__, __iadd__, etc) and rich comparisons (__eq__,
__lt__, etc.)
--
Gabriel Genellina
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