[Python-ideas] Bring back callable()

[MRAB]

On 24/11/2010 10:59, Georg Brandl wrote:
> Falls under "no new builtins" though.
>
It's not really new because it's in Python 2. :-)

> Georg
>
> Am 24.11.2010 00:19, schrieb Guido van Rossum:
>> I admit defeat on this one.
>>
>> On Tue, Nov 23, 2010 at 3:14 PM, Michael Foord
>> <fuzzyman at voidspace.org.uk>  wrote:
>>>
>>>
>>> On 23 November 2010 23:01, Antoine Pitrou<solipsis at pitrou.net>  wrote:
>>>>
>>>> Hello,
>>>>
>>>> Python 3 has removed callable() under the justification that's it's not
>>>> very useful and duck typing (EAFP) should be used instead. However,
>>>> it has since been felt by many people that it was an annoying loss;
>>>> there are situations where you truly want to know whether something is a
>>>> callable without actually calling it (for example when writing
>>>> sophisticated decorators, or simply when you want to inform the user
>>>> of an API misuse).
>>>>
>>>> The substitute of writing `isinstance(x, collections.Callable)` is
>>>> not good, 1) because it's wordier 2) because collections is really not
>>>> an intuitive place where to look for a Callable ABC.
>>>>
>>>> So, I would advocate bringing back the callable() builtin, which was
>>>> easy to use, helpful and semantically sane.
>>>
>>> +1 I find it useful in Python 2. You have to know its limitations, but it is
>>> still useful.
>>>