`unused-import` should observe `dummy-variables-rgx` setting

[macdjord]

Bug description

Python convention is that any variable name consisting entirely of underscores is to be considered a placeholder, used when a value needs to be assigned somewhere but you don't actually care about it after that. Thus no warnings should be emitted about such a variable being unused, overwritten, or changing type.

However, another common convention is to import the gettext() translation function as _ for convenience. Thus current best-practice is to use names of two or more underscores for placeholders.

test2.py:

"""Test"""

import prettyprinter as __

Configuration

No response

Command used

pylint test2.py

Pylint output

************* Module test2
test2.py:3:0: W0611: Unused prettyprinter imported as __ (unused-import)

------------------------------------------------------------------
Your code has been rated at 0.00/10 (previous run: 0.00/10, +0.00)

Expected behavior

No unused-import should be emitted if the module is imported with a name consisting entirely of underscores.

Pylint version

pylint 2.16.2
astroid 2.14.2
Python 3.11.2 (tags/v3.11.2:878ead1, Feb  7 2023, 16:38:35) [MSC v.1934 64 bit (AMD64)]

OS / Environment

Win10

Additional dependencies

No response

[DanielNoord]

I have never seen this pattern. How common is this?

[jacobtylerwalls]

I have seen the get_text alias as _.

I think we should accept this on the basis that unused-import should observe the dummy-variables-rgx config argument. Right now the check only checks for a hardcoded _. Then this message will have parity with unused-variable. The default for that variable already checks underscores at the start of a string.

Easy picking. Thanks for the report!

[RSTdefg]

Hello, I've looked into this issue and I'd like to work on it. Thanks!