Add --target-version pyXX option to CLI

[kdeldycke]

This is a feature request to add a --target-version pyXX to ruff.

The idea is to mimick Black by allowing any subset of the following values:

• --target-version py37
• --target-version py38
• --target-version py39
• --target-version py310
• --target-version py311
• ...

With the idea that you should include all Python versions that you want your code to run under (as Black does).

This exact format is also what blacken-docs CLI supports.

On a practical level, this will help me a lot as I already generates these flags in my build pipeline for Black and blacken-docs. These are generated dynamically by inspecting the pyproject.toml of my projects.

[kdeldycke]

For the record, this is adjacent to: #2039 and #2519

[charliermarsh]

Hey thanks for filing! This exact API actually is available on the CLI, I just hid it by accident in a prior commit 🤦

[kdeldycke]

Oh wow that's perfect! And incredibly fast!

I can test #2859 as soon as a release is publish.

[charliermarsh]

It should actually work even with existing versions (ruff check /path/to/file.py --target-version py311), it just won't show up in --help. If you see otherwise, let me know!

[kdeldycke]

Works indeed!

$ ruff --version
ruff 0.0.245

$ ruff check --fix-only --exit-zero --diff --target-version 311 ./.github/metadata.py
error: invalid value '311' for '--target-version <TARGET_VERSION>': Unknown version: 311 (try: "py37")

For more information, try '--help'.

$ ruff check --fix-only --exit-zero --diff --target-version py311 ./.github/metadata.py

No rush then to publish a new version of ruff.

Feel free to close this issue! :)

And thanks a lot for ruff, I played with it today and was able to get rid of iSort, Pyupgrade, Pylint, Pycln and Pydocstyle!

[charliermarsh]

Amazing, thanks for giving Ruff a try :)

[kdeldycke]

Just FYI, it doesn't supports multiple value yet, but that's a detail:

❯ ruff check --fix-only --exit-zero --target-version py38 --target-version py311 ./.github/metadata.py
error: the argument '--target-version <TARGET_VERSION>' cannot be used multiple times

Usage: ruff check [OPTIONS] [FILES]...

For more information, try '--help'.