On 2006-08-23, Terry Reedy <[EMAIL PROTECTED]> wrote:
>
> "faulkner" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]
>> what's wrong with hasattr(obj, '__call__')?
>
> I have the impression that this is not currently true for all callables .
> If not, this may be improved in the future.
>
>>> Antoon Pardon
>>> Is there a chance this will be reconsidered?
>
> The items in PEP 3100 have different levels of certainly. Some may even
> get changed after experience with the alpha versions. Guido is allowing a
> year from first alpha (early 2007?) to final release, instead of the
> current 4-5 months.
>
> There has been recent discussion since of iscallable and some other
> isxxxx()s. The points you mentioned were raised and considered. I don't
> remember if there was a decision for the present.
>
> Two of the bigger negatives for 'iscallable':
> 1. You cannot know for sure until you call and get a return.
Even that is not sure. Consider the following:
Bar = 1
def Foo():
Bar()
try:
Foo()
except ...:
warning("...")
Calling Foo will result in the same exception being raised as if
Foo wasn't callable, while in fact it is callable.
> 2. It does not say if the candidate is callable with any particular number
> or set of parameters.
But the "raise an exception" option doesn't make this distinction either.
A TypeError will be raised both when the object isn't callable or when
it is called with the wrong parameters.
--
Antoon Pardon
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