[Numpy-discussion] Warnings in NumPy SVN
Fernando.Perez at colorado.edu
Thu Apr 27 12:58:02 CDT 2006
David M. Cooke wrote:
> Fernando Perez <Fernando.Perez at colorado.edu> writes:
>>>On 4/27/06, Travis Oliphant <oliphant.travis at ieee.org> wrote:
>>>>The function (or macro) needs to implement the operation on the basic
>>>>data-type and if necessary set an error-flag in the floating-point
>>>>If anybody has time to help implement these basic operations, it would
>>>>be greatly appreciated.
>>>I can help. To make sure we don't duplicate our effort, let's do
>>>1. I will add place-holders for all the necessary functions to make
>>>them return "NotImplemented".
>>just a minor reminder:
>> raise NotImplementedError
>>is the standard idiom for this.
> Just a note: For __xxx__ methods, "return NotImplemented" is the
> standard idiom. See section 3.3.8 (Coercion rules) of the Python 2.4
> language manual:
> For most intents and purposes, an operator that returns
> NotImplemented is treated the same as one that is not implemented
> at all.
> I believe the idea is that it's not actually an error for an __xxx__
> method to not be implemented, as there are fallbacks.
You are right. It's worth remembering that the actual syntaxes are
/without/ quotes (as per the original msg), since these are actual python
builtins, not strings. That way they can be properly handled by their return
value or proper exception handling.
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