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Mon Apr 28 20:36:01 CEST 2014 · https://mail.python.org/pipermail/python-dev/2014-April/134364.html

Antoine's example works because list inherits from object. The more general
rule "compatible layout" only allows the rarest of cases to work --
basically the two classes involved must have a common base class and one of
the classes must not add any C-level fields to that base class's layout. I
would never count on this except in cases where this possibility is
documented (e.g. when one class is designed to be a mix-in for the other).

On Mon, Apr 28, 2014 at 11:24 AM, Antoine Pitrou <solipsis at pitrou.net>wrote:

> On Mon, 28 Apr 2014 20:45:48 +0300
> Paul Sokolovsky <pmiscml at gmail.com> wrote:
> >
> > So, is that it, or disjoint native types are supported as bases
> > somehow? Also, would someone know if a class-subclass case happens for
> > example in stdlib?
>
> Well, for instance this trivial example works:
>
> >>> class C(list, object): pass
> ...
> >>>
>
> Basically, if two classes have compatible layouts, you can inherit from
> both at once.
>
> Regards
>
> Antoine.
>
>
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-- 
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[Python-Dev] Multiple inheritance from builtin (C) types [still] supported in Python3?