I also find the example with :keyword a bit jarring at first glance, so I propose a double colon to alleviate the problem if we go in that direction. Compare:

    { :a, "b": x, :c }
    
    { ::a, "b": x, ::c }

On Fri, Apr 17, 2020 at 10:05 PM Rhodri James <rhodri@kynesim.co.uk> wrote:
On 17/04/2020 19:21, Andrew Barnert via Python-ideas wrote:
>> On Apr 17, 2020, at 01:58, Steven D'Aprano<steve@pearwood.info>  wrote:
>>
>> On Thu, Apr 16, 2020 at 09:21:05PM -0700, Andrew Barnert via Python-ideas wrote:
>>
>>> But I don’t see why that rules out the “bare colon” form that I and
>>> someone else apparently both proposed in separate sub threads of this
>>> thread:
>>>    { :a, "b": x, :c }
>>> as shorthand for:
>>>    { "a": a, "b": x, "c": c }
>>
>> I did a double-take reading that, because I visually parsed it as:
>>
>>    { :a,
>>      "b":
>>      x, :c
>>      }
>>
>> and couldn't work out what was going on.
>>
>> After saving this draft, closing the email, then reopening it, I read
>> the proposed dict the same way. So I don't think it was just a momentary
>> glitch.
> I honestly think, as you suggested at the end, that this may be just you. You’ve had similar reactions to other syntax that nobody else replicated, and I think that’s happening again here.

It's not just Steven.  After dusting my monitor to remove flyspecs, I
still couldn't find a natural way of reading that example.  I didn't
visually parse it quite the same, but the excess of punctuation still
encourage me to completely miss the '"b": x' part being a unit.

--
Rhodri James *-* Kynesim Ltd
_______________________________________________
Python-ideas mailing list -- python-ideas@python.org
To unsubscribe send an email to python-ideas-leave@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/7UU4MDSHLYFZ6UEDJBEZU4POL6QGGY45/
Code of Conduct: http://python.org/psf/codeofconduct/