[Python-Dev] Informal educator feedback on PEP 572 (was Re: 2018 Python Language Summit coverage, last part)

Ivan Pozdeev vano at mail.mipt.ru
Mon Jun 25 10:19:19 EDT 2018

On 25.06.2018 2:30, Greg Ewing wrote:
> Guido van Rossum wrote:
>> Greg seem to be +0 or better for (a)
> Actually, I'm closer to -1 on (a) as well. I don't like := as a
> way of getting assignment in an expression. The only thing I would
> give a non-negative rating is some form of "where" or "given".
"as" was suggested even before is became a keyword in `with'. ( if 
(re.match(regex,line) as m) is not None: <do smth> )

The only objective objection I've heard is it's already used in `import' 
and `with' -- but that's perfectly refutable.

> Brief summary of reasons for disliking ":=":
> * Cryptic use of punctuation
> * Too much overlap in functionality with "="
> * Asymmetry between first and subsequent uses of the bound value
> * Makes expressions cluttered and hard to read to my eyes


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