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Date: Fri, 28 Aug 2015 00:33:22 +1000
Subject: Re: isinstance() and multiple inheritance/ctypes
From: Chris Angelico <rosuav@gmail.com>
Cc: "python-list@python.org" <python-list@python.org>
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Xref: csiph.com comp.lang.python:95693

On Thu, Aug 27, 2015 at 10:59 PM, Steven D'Aprano <steve@pearwood.info> wrote:
> On Thu, 27 Aug 2015 09:14 am, Chris Angelico wrote:
>
>> On Thu, Aug 27, 2015 at 9:12 AM, Chris Angelico <rosuav@gmail.com> wrote:
>>> Or is there a magic __isinstance__
>>
>> Argh, keyed the wrong thing and sent the post prematurely. Meant to say:
>>
>> Or is there a magic __instancecheck__ method somewhere that I'm not aware
>> of?
>
> Yes -- see Terry Reedy's post.
>
> isinstance(inst, klass) ends up calling
>
> type(klass).__instancecheck__(klass, inst)

I'm aware that it _can_ exist, but I was asking if one _did_ exist.

ChrisA