[Python-ideas] Bring back callable()

Michael Foord fuzzyman at voidspace.org.uk
Wed Nov 24 00:14:29 CET 2010

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.


> Regards
> Antoine.
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> Python-ideas at python.org
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