[CI] Format python with ruff

[keith]

Ruff is a faster and more modern python formatter. This swaps out using
mojo format for python with ruff.

[github-actions]

The PR title does not conform to the '[<Project>] Title' format. Please update the PR title.

Typical [<Project>] values include:

• [stdlib] — indicates a change to the Mojo standard library code
• [docs] — indicates a change to the documentation

It's okay to include multiple labels on a PR that affect multiple areas of work.

Thank you for contributing to Mojo!🔥

You can also use a tool like www.regex101.com to see why your PR title fails to conform. Use ^(Revert ")?(\[\S.*\]\s?)+\s+[a-zA-Z`].* as the regex to test and Format python with ruff as the test string.

All good now, thanks!🫸🫷

[martinvuyk]

@keith I think this will cause conflicts for every PR until mojo format behaves the same. I normally run mojo format ./stdlib/ for example. Are there plans to change mojo format to behave like ruff instead of black formatter?

[martinvuyk]

@keith the tool having a static config option already sold me on wanting to use it 😄 (although now I read that black formatter also has that, I had no idea). Is there another option to avoid the difference in newline in PR #3822 (file) ?

[keith]

I think we might just want to stop mojo format from running on python, but I'm hoping @JoeLoser can provide an opinion here

[martinvuyk]

I think we might just want to stop mojo format from running on python, but I'm hoping @JoeLoser can provide an opinion here

Just an idea: add a flag that is default mojo only where you can also make mojo format run on any extension e.g. mojo format -e py -e ipynb. That way for people doing hybrid projects they can leverage mojo format directly, and those who don't want to aren't forced by it.

[walter-erquinigo]

Hi! I'm the maintainer of mojo format and we never really intended to have mojo format be used on python files =P
So, the change that we'll do is to prevent it from touching any non-mojo files. Hopefully I'll land that this week.

[JoeLoser]

LGTM but you'll need to split this across two PRs since the .pre-commit-config.yaml isn't managed by Copybara whereas the rest of the files are I believe. Also, in a follow-up PR, can you add Ruff to the contributing docs for formatting Python-related parts to avoid future confusion?

[patrickdoc]

!sync (for testing)

[patrickdoc]

!sync (testing 2)

[JoeLoser]

LGTM but you'll need to split this across two PRs since the .pre-commit-config.yaml isn't managed by Copybara whereas the rest of the files are I believe. Also, in a follow-up PR, can you add Ruff to the contributing docs for formatting Python-related parts to avoid future confusion?

Gentle ping here @keith as pretty much every PR from other contributors keeps modifying the my_module.py file since mojo format formats it and then it breaks the lint job internally requiring me to fix up each synced PR.

[walter-erquinigo]

https://github.com/modularml/modular/pull/52586 should fix the mblack part