[ENHANCEMENT] black formatting

[dbrakenhoff]

As proposed by @martinvonk in #389, use black formatting, especially to make the type hinting prettier in function definitions.

One argument I had against doing this for the entire code base was that the git blame would be affected, but turns out they've thought about this: https://black.readthedocs.io/en/stable/guides/introducing_black_to_your_project.html

So +1 from me for black formatting for pastas!

[martinvonk]

The need to follow up on this change is lower because I formatted the lines affected by type hinting (#441) by hand🙃. However, I am in favor of formatting Pastas with black. Maybe we could format the code with black in a separate branch to see how much of the code is affected and how much this messes up git blame. Maybe it is not as much as we fear and we can make a better assessment of the implications.

[raoulcollenteur]

+1 for black and automating this through GH actions if possible.

[raoulcollenteur]

Before this issue can be closed:

• The line-wrap seems to be 88 now, instead of the old 79, that and the fact that we use black formatting should be written in the Docs. https://pastas.readthedocs.io/en/latest/developers/index.html
• If we apply black, I think it would be good to automate that with GH actions: https://black.readthedocs.io/en/stable/integrations/github_actions.html

[dbrakenhoff]

Correct, line-length is set to 88 by black by default.
GitHub Actions will be set in a separate PR/commit.

FYI, for locally ensuring the git blame is rendered correctly (ignoring this commit):

git config blame.ignoreRevsFile .git-blame-ignore-revs

08fe3d7 add mention of black code formatting to docs

[dbrakenhoff]

I can add linting with Black step (replacing the old flake8 step) which checks whether code is black formatted prior to running tests.

We can automate the black formatting and commit it directly to a PR (https://peterevans.dev/posts/github-actions-how-to-automate-code-formatting-in-pull-requests/) but this does not work on forks, so not sure how useful that is. Running black is very easy, so I'm ok with keeping that manual step... but let me know what you think.

[martinvonk]

pastas/.github/pull_request_template.md

Line 7 in 59e85ab

- [ ] PEP8 compliant code

Maybe we can change this to

• formatt code with black

and close this issue?

[raoulcollenteur]

I agree with running black formatting locally now. PR's will fail anyway when it is not black formatted.

@martinvonk I changed the template, so following your suggestions I am closing this Issue :)