New check: Walrus operator recommended

[nickdrozd]

Current problem

Consider this still-common pattern:

match = re.match(regex, string)
if match:
    do_stuff(match)

Desired solution

As of Python 3.8, this can be rewritten with the "walrus":

if (match := re.match(regex, string)):
    do_stuff(match)

Pylint should recommend using the walrus operator in situations like this.

Additional context

See https://www.python.org/dev/peps/pep-0572/

[Pierre-Sassoulas]

Thank you, nice suggestion !

[cdce8p]

Opened a PR for it: #4876

[Pierre-Sassoulas]

Moving to 2.11 as I feel we already have a lot of things in 2.10 and we're sitting on great unreleased performance improvement.