osdir.com


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Python-Dev] PEP 572: Do we really need a ":" in ":="?


On Thu, Jul 5, 2018 at 7:47 PM Yury Selivanov <yselivanov.ml at gmail.com>
wrote:

> I think I tried a variation of your proposal here
> https://mail.python.org/pipermail/python-dev/2018-April/152939.html
> and nobody really liked it.
>
> Right. I now recall your proposal.  I think I did not support it at the
time because I was against having expressions with side-effects regardless
of syntax.  Now, as I mentioned, in the current form the PEP makes a strong
case for allowing a limited form of variable assignment in expressions.  I
also think that the dreadfulness of mistyping = where == is expected is
exaggerated.  In all motivating cases, := is used to introduce new bindings
rather than rebinding existing names.  Automated code checkers can easily
warn users when they rebind variables in if statements and suggest that
they silence the warnings with redundant (..) if they really want what they
wrote.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-dev/attachments/20180705/32ce3cfd/attachment.html>