[Python-Dev] PEP487: Simpler customization of class creation

Guido van Rossum guido at python.org
Sun Jul 24 11:20:40 EDT 2016

I am very much against this. The two are not at all like each other. Also,
what's the use case?

On Sunday, July 24, 2016, Martin Teichmann <lkb.teichmann at gmail.com> wrote:

> Hi list, Hi Nick,
> Sorry for my delayed response, it is summer here...
> > However, phrasing it that way suggest that it's possible we *did* miss
> > something in the PEP: we haven't specified whether or not __set_name__
> > should be called when someone does someone does "cls.attr = descr".
> > Given the name, I think we *should* call it in that case, and then the
> > semantics during class creation are approximately what would happen if
> > we actually built up the class attributes as:
> >
> >     for attr, value in cls_ns.items():
> >         setattr(cls, attr, value)
> That's a very good point and actually easy to solve: we would just
> need to override type.__setattr__ to do so. Actually, it is already
> overridden, so we just need to add code to type.__setattr__ to also
> call __set_name__.
> One could be of the other standpoint that in your above example it's
> the duty of the caller of setattr to also call __set_name__. It would
> be pretty easy to add a line in the loop that also calls
> __set_owner__.
> Greetings
> Martin
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--Guido (mobile)
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