Have you seen PEP 637? IIRC it has discussions on a[] and a[*x]. Note that
it was rejected, but the idea of a[*x] is being resurrected for PEP 646.
On Fri, Aug 13, 2021 at 5:43 AM Matsuoka Takuo <motogeom...@gmail.com>
wrote:
> Dear Developers,
>
> Given a subscriptable object s, the intended rule for the notation for
> getting an item of s seems that, for any expression {e}, such as
> "x, ",
> s[{e}]
> (i.e., s[x, ] if {e} is "x, ") means the same as
> s[({e})]
> (i.e., s[(x, )] in the considered case), namely, should be evaluated
> as s.__getitem__(({e})) (or s.__class_getitem__(({e})) when that
> applies). If this is the rule, then it looks simple and hence
> friendly to the user. However, there are at least two exceptions:
>
> (1) The case where {e} is the empty expression "":
> The expression
> s[]
> raises SyntaxError instead of being evaluated in the same way as
> s[()] is.
>
> (2) The case where {e} contains "*" for unpacking:
> An expression containing the unpacking notation, such as
> s[*iterable, ]
> raises SyntaxError instead of being evaluated in the same way as
> s[(*iterable, )] in this example, is.
>
> Are these (and other if any) exceptions justified? If not, I propose
> having the described rule to have full effect if that would simplify
> the syntax. This would affect currently working codes which rely on
> SyntaxError raised in either of the described ways (through eval, exec
> or import??). I wonder if reliance on SyntaxError in these cases
> should be supported in all future versions of Python.
>
> Best regards,
> Takuo Matsuoka
> _______________________________________________
> Python-ideas mailing list -- python-ideas@python.org
> To unsubscribe send an email to python-ideas-le...@python.org
> https://mail.python.org/mailman3/lists/python-ideas.python.org/
> Message archived at
> https://mail.python.org/archives/list/python-ideas@python.org/message/V2WFMNVJLUBXVQFPNHH4TJNRYNPK2BKJ/
> Code of Conduct: http://python.org/psf/codeofconduct/
>
--
--Guido van Rossum (python.org/~guido)
*Pronouns: he/him **(why is my pronoun here?)*
<http://feministing.com/2015/02/03/how-using-they-as-a-singular-pronoun-can-change-the-world/>
_______________________________________________
Python-ideas mailing list -- python-ideas@python.org
To unsubscribe send an email to python-ideas-le...@python.org
https://mail.python.org/mailman3/lists/python-ideas.python.org/
Message archived at
https://mail.python.org/archives/list/python-ideas@python.org/message/L6CXI6OWIXS7ADXWHE4K2FJUMQSAOAYI/
Code of Conduct: http://python.org/psf/codeofconduct/
