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[Python-ideas] An even simpler customization of class creation

Nick Coghlan ncoghlan at gmail.com
Mon Mar 2 10:45:38 CET 2015 
On 1 Mar 2015 19:28, "Martin Teichmann" <lkb.teichmann at gmail.com> wrote:
>
> > Aye, I like this design, it just wasn't until I saw it written out
> > fully that it finally clicked why restricting it to subclasses let
> > both zero-argument super() and explicit namespace access to the
> > defining class both work. Getting the latter to also work is a
> > definite strength of your approach over mine.
>
> That said, I would love if it was just possible to use super() in
> classmethods called from the __init__ of a metaclass. Until
> now, the __class__ of a method is only initialized after
> the metaclasses __init__ has run.
>
> Fortunately, this is easily changeable: it is possible to move the
> initialization of __class__ into type.__new__. As the class is
> (typically) created there, that is about as early as possible.

Unfortunately, it's too early - we can't control whether or not subclasses
actually return the result of type.__new__ from their own __new__
implementation, so that object could have been replaced by something else
by the time __init__ gets called.

However, it may be feasible to move it into type.__init__. That way class
methods would start working properly as soon as the metaclass __init__
implementation had called up into type.__init__.

Regards,
Nick.
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