[Python-Dev] PEP 572: Assignment Expressions (original) (raw)

Ethan Furman ethan at stoneleaf.us
Fri Apr 20 14:47:17 EDT 2018

On 04/20/2018 11:31 AM, Christoph Groth wrote:

Ethan Furman wrote:

On 04/20/2018 11:15 AM, Christoph Groth wrote:

OK, but then how about introducing assignment expressions with the "=" operator but requiring extra parens (similar to how modern C compilers warn about assignment expressions without parens), e.g.

Using a single "=" for assignment expressions isn't going to happen. Period. Huh, I didn't want to irritate anyone!

No worries. It's just not going to happen. ;)

Guido wrote [1] on python-ideas:

I also think it's fair to at least reconsider adding inline assignment, with the "traditional" semantics (possibly with mandatory parentheses). This would be easier to learn and understand for people who are familiar with it from other languages (C++, Java, JavaScript). I interpreted this in the way that he at least doesn't rule out "= with parens" completely. Perhaps he meant ":= with parens", but that would seem redundant.

Ah. I believe he was referring to not having a statement-local binding, but a normal binding instead (so either local or global depending on where the expression occurred).

-- Ethan

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