Quoting levels are a bit messed up in David's post, I've tried to fix
them bu apologies if I'm attributing words to David that he didn't
write.
On Thu, Sep 24, 2020 at 07:04:31PM -1000, David Mertz wrote:
> Is this a breaking change? It feels borderline.
>
> > Keyword-only subscripts are permitted. The positional index will be
> > the empty tuple:
> >
> > obj[spam=1, eggs=2]
> > # calls type(obj).__getitem__(obj, (), spam=1, eggs=2)
>
>
> I.e. consider:
>
> >>> d = dict()
> >>> d[()] = "foo"
> >>> d
> {(): 'foo'}
>
>
> I don't really object to this fact, and one could argue it's not a breaking
> change since a built-in dict will simply raise an exception with keyword
> arguments. However, it does make the empty tuple the "default key" for new
> objects that will accept keyword indices.
I agree with Ricky that the choice of empty tuple should be justified
better by the PEP, and alternatives (None, NotImplemented) discussed.
But I don't think this is a breaking change. Can you explain further
what you think will break?
--
Steve
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