[Python-ideas] PEP 505: None-aware operators

[Abe Dillon]

>
> The two statements you wrote are not the same. The first statement will
> error out if person is None.

That's my bad. I was copying off of an erroneous example. Thanks for
correcting me.

The proposed None-aware operators are specifically designed to handle
> variables that may be None.
>
Yes, I think the syntax that you've landed on is confusing enough that it
opens the door to more errors than it closes. Just reading "(a?.b ?? c).d?.e"
and "await a?.b(c).d?[e]"


On Wed, Jul 25, 2018 at 6:06 PM, Nicholas Chammas <
nicholas.chammas at gmail.com> wrote:

> On Wed, Jul 25, 2018 at 6:11 PM Abe Dillon <abedillon at gmail.com> wrote:
>
>> The problem here is not whether it's explicit. It's about Readability and
>> conciseness. Using symbols in place of words almost always harms
>> readability in favor of conciseness.
>>
>> value = person.name if person.name else person
>>
>> almost reads like english (aside from being a weird and totally uncommon
>> use case)
>>
>> value = person?.name
>>
>> Is a huge step towards the concise illegible soup of symbols that Perl is
>> famous for. It's a huge No from me.
>>
>
> The two statements you wrote are not the same. The first statement will
> error out if person is None. The proposed None-aware operators are
> specifically designed to handle variables that may be None.
>
> The first statement should instead read:
>
>     value = person.name if person is not None else person
>
> That's what `value = person?.name` means.
>
> As others have pointed out, I suppose the fact that multiple people have
> messed up the meaning of the proposed operators is concerning. Perhaps the
> PEP could be improved by adding some dead simple examples of each operator
> and an equivalent statement that doesn't use the operator, to better
> illustrate their meaning. But I gather that will do little in the way of
> addressing some of the stronger objections raised here.
>
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