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[Python-Dev] PEP 572 semantics: all capabilities of the assignment statement

Chris Angelico rosuav at gmail.com
Thu Jul 5 01:19:56 EDT 2018 
On Thu, Jul 5, 2018 at 3:15 PM, Guido van Rossum <guido at python.org> wrote:
> Let me be slightly contrarian. :-)
>
> On Wed, Jul 4, 2018 at 9:12 PM Chris Angelico <rosuav at gmail.com> wrote:
>> 2) Is the result of the expression the modified value or the original?
>
> Someone (sadly I forget who) showed, convincingly (to me anyways :-) that it
> should return whatever the `__iadd__` method returns, or (if there isn't
> one) the result of `a = a + b`.

I happen to feel the same way, but it does destroy the elegance of "x
:= expr" having the exact same value as "expr", and ALSO having the
exact same value as "x". But yes, the biggest argument is the lack of
use cases, for both iadd and unpacking.

ChrisA
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