On Tue, Feb 18, 2020 at 12:20 AM Soni L. <fakedme...@gmail.com> wrote:
>
> I looked at the PEP for None-aware operators and I really feel like they
> miss one important detail of Python's data model:
>
> >>> {}[0]
> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
> KeyError: 0
> >>> [][0]
> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
> IndexError: list index out of range
>
> that is: missing items raise, rather than being None. as such I feel
> like None-aware operators would encourage ppl to put None everywhere,
> which from what I can tell, goes completely against Python's data model.
>
> however, exception-aware operators could be a potential alternative that:
>
> 1. works with existing code (no need to go shoving None everywhere)
> 2. works in lambdas
> 3. ends up being more useful?
>
> I don't know what the potential syntax would look like. perhaps
> something along the lines of:
>
> exception-raising-expression ?: value-if-exception-raised
>
> or:
>
> exception-raising-expression ? (IndexError, KeyError, Etc) :
> value-if-exception-raised
>
> but, thoughts?
See PEP 463 and the many MANY posts about it.
ChrisA
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