RetroSearch Browse

Wed Nov 22 15:29:42 EST 2017 · https://mail.python.org/pipermail/python-dev/2017-November/150723.html

Inasmuch as I get to opine, I'm +1 on SyntaxError. There is no behavior for
that spelling that I would find intuitive or easy to explain to students.
And as far as I can tell, the ONLY time anything has ever been spelled that
way is in comments saying "look at this weird edge case behavior in Python."

On Nov 22, 2017 10:57 AM, "Jelle Zijlstra" <jelle.zijlstra at gmail.com> wrote:

2017-11-22 9:58 GMT-08:00 Guido van Rossum <guido at python.org>:

> Wow, 44 messages in 4 hours. That must be some kind of record.
>
> If/when there's an action item, can someone summarize for me?
>
> The main disagreement seems to be about what this code should do:

    g = [(yield i) for i in range(3)]

Currently, this makes `g` into a generator, not a list. Everybody seems to
agree this is nonintuitive and should be changed.

One proposal is to make it so `g` gets assigned a list, and the `yield`
happens in the enclosing scope (so the enclosing function would have to be
a generator). This was the way things worked in Python 2, I believe.

Another proposal is to make this code a syntax error, because it's
confusing either way. (For what it's worth, that would be my preference.)

There is related discussion about the semantics of list comprehensions
versus calling list() on a generator expression, and of async semantics,
but I don't think there's any clear point of action there.

> --
> --Guido van Rossum (python.org/~guido)
>
> _______________________________________________
> Python-Dev mailing list
> Python-Dev at python.org
> https://mail.python.org/mailman/listinfo/python-dev
> Unsubscribe: https://mail.python.org/mailman/options/python-dev/jelle.
> zijlstra%40gmail.com
>
>

_______________________________________________
Python-Dev mailing list
Python-Dev at python.org
https://mail.python.org/mailman/listinfo/python-dev
Unsubscribe: https://mail.python.org/mailman/options/python-dev/
mertz%40gnosis.cx
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-dev/attachments/20171122/a82a01ad/attachment.html>

Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Showing content from https://mail.python.org/pipermail/python-dev/2017-November/150723.html below:

[Python-Dev] Tricky way of of creating a generator via a comprehension expression