Agree with Paul. The PEP is well thought out and well presented, but I really don’t think we need this in Python (and I say this as someone who uses it regularly in C/C#).

-1 on the idea; no disrespect intended toward to people who did a lot of work on it.

Top-posted from my Windows phone

From: Paul Moore
Sent: Tuesday, April 17, 2018 6:31
To: David Mertz
Cc: Nick Coghlan; Python-Dev
Subject: Re: [Python-Dev] PEP 572: Assignment Expressions

On 17 April 2018 at 14:07, Paul Moore <p.f.moore@gmail.com> wrote:

> On 17 April 2018 at 14:01, David Mertz <mertz@gnosis.cx> wrote:

>> Strongly agree with Nick that only simple name targets should be permitted

>> (at least initially). NONE of the motivating cases use more complex targets,

>> and allowing them encourages obscurity and code golf.

>

> I also agree. Originally I would have said why not allow them, it's a

> potentially useful generalisation. But Nick's examples pretty clearly

> demonstrate that there are a lot of unclear edge cases involved, and

> even though "prevent people writing ugly code" is explicitly stated as

> a non-goal in the PEP, that doesn't mean it's OK to allow an obvious

> bug magnet with no clear use cases.

I should also point out that I remain -0 on this proposal (I'd already

said this on python-ideas, but I should probably repeat it here). For

me, the use cases are mostly marginal, and the major disadvantage is

in having two forms of assignment. Explaining to a beginner why we use

a := b in an expression, but a = b in a statement is going to be a

challenge.

The fact that the PEP needs a section covering all the style guide

warnings we feel are needed seems like it's a warning bell, too.

Paul

_______________________________________________

Python-Dev mailing list

Python-Dev@python.org

https://mail.python.org/mailman/listinfo/python-dev

Unsubscribe: https://mail.python.org/mailman/options/python-dev/steve.dower%40python.org