Auto-detect minimal Python version

[kdeldycke]

My proposition is to have pyupgrade auto detect the minimal Python version targeted by a project and set by itself the --py3-plus / --py36-plus / (...) / --py311-plus option flags.

I hacked this autodetection feature in my GitHub workflows by inspecting the pyproject.toml.

Note this feature is also considered by black and discussed for mypy.

[SamirPS]

If a new version of python is out you will need to modify the file no ? Can we erase the check <= 11 ?

[kdeldycke]

Oh I see. I initially added that upper limit to make sure I'll not feed pyupgrade with options not recognized yet. Like in the time frame between new major Python versions and pyupgrade releases.

But I'm OK with removing that limit. It might be helpful to have it fail in this time-frame, as a reminder to have pyupgrade updated! :)

Just fixed this in kdeldycke/workflows@211f3a4

[SamirPS]

Does PyUpgrade have a error if I enter --py-314-plus ?

[kdeldycke]

It does:

❯ pyupgrade --py34-plus ./meta_package_manager/tests/test_cli_installed.py
usage: pyupgrade [-h] [--exit-zero-even-if-changed] [--keep-percent-format] [--keep-mock]
                 [--keep-runtime-typing] [--py3-plus] [--py36-plus] [--py37-plus] [--py38-plus]
                 [--py39-plus] [--py310-plus] [--py311-plus]
                 [filenames ...]
pyupgrade: error: unrecognized arguments: --py34-plus

[SamirPS]

I thinks you change need to add your code here : https://github.com/asottile/pyupgrade/blob/main/pyupgrade/_main.py

[asottile]

no thanks -- that would involve reading configuration files of which I don't want anything to do with that complexity

[kdeldycke]

OK no worries, I understand the policy of keeping pyupgrade to the essentials. I'll keep my hack confined to my GitHub workflows then.

[kdeldycke]

Oh, and thanks @asottile for pyupgrade: it's a really cool project. Love it!