gh-120417: Add #noqa to load_tests() in tests

[vstinner]

Ignore linter "imported but unused" warnings in tests when the linter doesn't understand why the import is important.

• Issue: Remove unused imports from the stdlib #120417

[encukou]

Could you add/link an explanation about what noqa: F401 means and how to maintain it?

In my projects, I've avoided these warning by adding public names to __all__, rather than with a cryptic comment.

[vstinner]

Could you add/link an explanation about what noqa: F401 means and how to maintain it?

It's a "standard" linter command to ignore "imported but unused" warning on the current line.

It was discussed at #120421.

[serhiy-storchaka]

Could you add an exception for load_tests in a global configuration file?

[vstinner]

@serhiy-storchaka:

Could you add an exception for load_tests in a global configuration file?

I have no idea on how to do that.

@AlexWaygood: Is it something supported by Ruff by example?

[AlexWaygood]

@AlexWaygood: Is it something supported by Ruff by example?

we support ignoring certain errors for filenames that match certain patterns. But I don't think we support ignoring F401 for specific symbols, no. It might be a reasonable feature request.

[serhiy-storchaka]

Can it be ignored for Lib/test/*/**/__main__.py? All these files are the same.

[AlexWaygood]

Yes, in Ruff you can do that via the CLI using --config='lint.per-file-ignores = {"Lib/test/*/**/__main__.py" = ["F401"]}'. Or in a pyproject.toml configuration file, you can do this:

[tool.ruff.lint.per-file-ignores]
"Lib/test/*/**/__main__.py" = ["F401"]

Or this in a ruff.toml configuration file:

[lint.per-file-ignores]
"Lib/test/*/**/__main__.py" = ["F401"]

[vstinner]

Can it be ignored for Lib/test/*/**/__main__.py? All these files are the same.

It means that other unused imports can no longer be catched.

[vstinner]

In total, ruff check|grep F401 returns 173 lines. These load_tests are not the worst, so I prefer to close this PR for now.