[Python-Dev] assignment expressions: an alternative proposal

[Steven D'Aprano]

On Tue, Apr 24, 2018 at 11:05:57AM -0400, Yury Selivanov wrote:

> Well, `my_func(a=(b:=foo))` or `my_func(b:=foo)` are also barely
> readable to my eye.

There's no advantage to using binding-expressions unless you're going to 
re-use the name you just defined, and that re-use will give you a hint 
as to what is happening:

    my_func(arg, buffer=(buf := [None]*get_size()), size=len(buf))


> My expectation is that users won't use any form
> of assignment expressions in function calls, it's painful with both
> proposals.

If binding-expressions are accepted into the language, I will certainly 
use them in function calls, *if and when appropriate*. I don't expect it 
will be common, but I'm sure it will happen.



-- 
Steve