[Python-ideas] Support other dict types for type.__dict__

[David Townshend]

On Fri, Feb 24, 2012 at 3:08 AM, Nick Coghlan <ncoghlan at gmail.com> wrote:

> On Fri, Feb 24, 2012 at 9:34 AM, Victor Stinner
> <victor.stinner at haypocalc.com> wrote:
> > Hi,
> >
> > I'm trying to create read-only objects using a "frozendict" class.
> > frozendict is a read-only dict. I would like to use frozendict for the
> > class dict using a metaclass, but type.__new__() expects a dict and
> > creates a copy of the input dict.
>
> Do you have a particular reason for doing it that way rather than just
> overriding __setattr__ and __delattr__ to raise TypeError?
>
> Or overriding the __dict__ descriptor to return a read-only proxy?
>
> There are a *lot* of direct calls to the PyDict APIs in the object
> machinery. Without benchmark results clearly showing a negligible
> speed impact, I'd be -1 on increasing the complexity of all that code
> (and making it slower) to support niche use cases that can already be
> handled a couple of other ways.
>
> Cheers,
> Nick.
>
> --
> Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia
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Can't this also be done using metaclasses?
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