[Python-ideas] Using "||" (doubled pipe) as the null coalescing operator?

[Guido van Rossum]

Using "?" as a (pro)noun is even worse than using it as an
operator/modifier.

On Thu, Sep 24, 2015 at 3:28 PM, Erik <python at lucidity.plus.com> wrote:

> On 24/09/15 04:00, Nick Coghlan wrote:
>
>>  data = data if ? is not sentinel else default()
>>
>
> This reads OK in a short example like this and when using word-based
> operators such as "is not". However, it's a bit clumsy looking when using
> operators spelled with punctuation:
>
> data = data if ? != None else default()
> data = data if foo <= ? <= bar else default()
>
> > title = user_title if ? is not None else local_default_title if ? is not
> None else global_default_title
>
> I don't think I like the way '?' changes its target during the line in
> this example.
>
> For example, the equivalent of the admittedly-contrived expression:
>
> foo = bar if foo is None else baz if baz is not None else foo.frobnicate()
>
> is:
>
> foo = bar if ? is None else baz if ? is not None else foo.frobnicate()
>
> ... so you still have to spell 'foo' repeatedly (and only due to the
> subtle switch of the '?' target, which might go away (or be added) during
> code maintenance or refactoring).
>
>
> Also, if '?' is sort of a short-cut way of referencing the LHS, then one
> might naively expect to be able to write this:
>
> [(x, y) for x in range(5) if ? < 3 for y in range(5) if ? > 2]
>
> Regs, E.
>
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-- 
--Guido van Rossum (python.org/~guido)
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