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

[Chris Angelico]

On Mon, Jul 23, 2018 at 7:51 AM, Giampaolo Rodola' <g.rodola at gmail.com> wrote:
> On Sun, Jul 22, 2018 at 10:55 PM Chris Angelico <rosuav at gmail.com> wrote:
>>
>> On Mon, Jul 23, 2018 at 6:43 AM, Giampaolo Rodola' <g.rodola at gmail.com> wrote:
>> > On Sun, Jul 22, 2018 at 10:01 PM Chris Angelico <rosuav at gmail.com> wrote:
>> >>
>> >> On Mon, Jul 23, 2018 at 1:09 AM, Giampaolo Rodola' <g.rodola at gmail.com> wrote:
>> >> > On Sun, Jul 22, 2018 at 3:38 PM Chris Angelico <rosuav at gmail.com> wrote:
>> >> > I find it less explicit mainly because it does 3 things at once: check
>> >> > if attribute is None, use it if it's not None and continue the
>> >> > evaluation from left to right. I find that logic to be more explicit
>> >> > when living on different lines or is clearly delimited by keywords and
>> >> > spaces. ? has no spaces, it's literally "variable names interrupted by
>> >> > question marks" and evaluation can stop at any time while scanning the
>> >> > line from left to right. Multiple "?" can live on the same line so
>> >> > that's incentive to write one-liners, really, and to me one-liners are
>> >> > always less explicit than the same logic split on multiple lines.
>> >>
>> >> Ah, I see what you mean. Well, think about what actually happens when
>> >> you write "lst.sort()". In terms of "hidden behaviour", there is far
>> >> FAR more of it in existing syntax than in the new proposals.
>> >
>> > I am not sure I'm following you (what does lst.sort() have to do with "?"?).
>>
>> The "." in "lst.sort" is an operator. How much hidden behaviour is
>> there in that? Do you actually even know every possible thing that can
>> happen? Don't feel bad if you don't - it's not an indictment of your
>> quality as a programmer, but an acknowledgement that Python's
>> attribute access is incredibly complicated.
>
> I'm [not] going to engage into a discussion about the analogy between "?"
> and "." because simply there is none. It doesn't prove anything except
> that you're not really interested in having a serious discussion about
> the pros and cons of this PEP: you just want it to happen no matter
> what.

That's because the dot already exists in the language, and you have
become so accustomed to it that you don't see it any more. You've just
proven my point.

ChrisA