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[Python-Dev] PEP 558: Defined semantics for locals()

Paul Moore p.f.moore at gmail.com
Sun May 26 07:53:42 EDT 2019 
On Sun, 26 May 2019 at 12:23, Chris Angelico <rosuav at gmail.com> wrote:
>
> On Sun, May 26, 2019 at 8:07 PM Steven D'Aprano <steve at pearwood.info> wrote:
> > On Sun, May 26, 2019 at 08:44:33AM +1000, Chris Angelico wrote:
> >
> > > From my reading of the description, you could also "assert a is b" -
> > > is that correct?
> >
> > Yes, that's already the behaviour.
> >
> > py> def demo():
> > ...     a = locals()
> > ...     b = locals()
> > ...     print(a is b)
> > ...
> > py> demo()
> > True
> >
>
> Sure, but this PEP is all about defining things that weren't
> previously defined, so I wanted to clarify intent rather than current
> behaviour.

+1 on the PEP being explicit over this. Even though it's current
behaviour, it's surprising and making a clear and definitive statement
that the PEP intends to make the behaviour part of the language
definition and not just a CPython detail, is IMO worthwhile.

Paul
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