[Python-ideas] Allow isinstance second argument to be a set of types

MRAB python at mrabarnett.plus.com
Mon Jul 4 21:53:47 CEST 2011


On 04/07/2011 20:41, Amaury Forgeot d'Arc wrote:
> Hi,
>
> 2011/7/4 Antoine Pitrou<solipsis at pitrou.net>:
>> Le lundi 04 juillet 2011 à 10:52 -0700, Gregory P. Smith a écrit :
>>> note that a fast lookup implies exact type and not subclass making my
>>> point silly... at which point you're back to iterating so I suspect
>>> supporting arbitrary iterables is actually how this will be
>>> implemented regardless.
>>
>> Indeed. Note that the tuple case should remain fast, and therefore
>> special-cased (or the general list/tuple case, since the difference in C
>> is rather small).
>
> Arbitrary iterables, arbitrarily nested...
> beware of objects which are also their first element, like str('a')...
>
Probably not arbitrarily nested, just a type (type(t) is type) or an
iterable yielding types. Anything else would raise an exception.



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