DEV - Set a canonical default Python version (3.12)

[trallard]

This is another stack to #838 and intended to be merged after #841

Description

While reviewing #841, @peytondmurray suggested bumping the default Python version used for CI, Docker images, and the like.

This PR bumps us from 3.10 to 3.12:

• Adds a .python-version-default file to serve as the canonical source of truth across all the places where we set Python versions
• Updates ./github/workflows to use this new file to get the canonical Python version
• Bumps the Python version in other places

Pull request checklist

• Did you test this change locally?
• Did you update the documentation (if required)?
• Did you add/update relevant tests for this change (if required)?

Additional information

How to test

[peytondmurray]

I was wondering if there was any other way to solve this, but this seems reasonable.

The only ones I could find that were missed are the entries in pyproject.toml. Do we need to worry about those?

Also the tests are failing, but I think that's from the previous PR that got merged.

[jaimergp]

This is a better way of consolidating the information. My two cents:

• There's no standard filename or location for this type of file, but I do see some projects using this filename. There are others like simply .python-version (no -default).
• Parsing from a plain text file might introduce accidental trailing whitespace. Usually tricky to debug. We could make sure that the file is always whitespace stripped with a pre-commit rule for that file only. Or if there's none, a simply Python step in the workflow:

- name: Make sure python-version has no whitespace
  shell: python
  run: |
    from pathlib import Path
    assert Path(".python-version-default").read_text().strip() == Path(".python-version-default").read_text()

• The environment.yml file python version might get out of date. There's a comment about it but if someone updates the python-version-default file they might not see the environment.yml one. So I suggest we add a little check step like above:

- name: Make sure python-version has no whitespace
  shell: python
  run: |
    from pathlib import Path
    assert f'- python={Path(".python-version-default").read_text().strip()}' in Path("environment.yml").read_text()

[peytondmurray]

Yep, now that you mention it pre-commit isn't hitting this file with the current configuration. Can we change it to strip trailing whitespace everywhere? I don't actually know of a single situation in which I'd want trailing whitespace.

  - repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v4.6.0
    hooks:
      - id: trailing-whitespace
        files: ".*\\.py"
      - id: check-added-large-files
      - id: check-toml
      - id: end-of-file-fixer
      - id: trailing-whitespace

[jaimergp]

And maybe make sure end-of-file-fixer doesn't add the extra newline?

[trallard]

Also the tests are failing, but I think that's from the previous PR that got merged.

@peytondmurray No this is the same original error in my PR about the pip key rather than from the previous PR

The environment.yml file python version might get out of date. There's a comment about it but if someone updates the python-version-default file they might not see the environment.yml one. So I suggest we add a little check step like above:

My goal is to eventually just get rid of the environment.yaml files; right now, the only one that might be going stale is the dev-environment.yaml file, as we are otherwise using the python-default-version file to set the Python version elsewhere. So for practical purposes the Python version would always be correct, at least on CI.

Now if someone uses that locally then that might be out of date 🤷🏽‍♀️ but I see the proposed workflow as already more robust sans the end of file/whitespace thingy.

[trallard]

The only ones I could find that were missed are the entries in pyproject.toml. Do we need to worry about those?

Why would we need to change these? These are the Python requires 3.8 so unless we are dropping 3.8-11 we do not need to change these

[trallard]

I fixed the pre-commit hooks, so there should be no need to add extra steps.

There's no standard filename or location for this type of file, but I do see some projects using this filename. There are others, such as simply .python-version (no default).

Since there is no standard, I used python-version-default for symmetry with what we were using in some GH workflows (env variable), but I am not privy to keeping or changing the name in case either of you have a preference @jaimergp @peytondmurray

[peytondmurray]

I'm totally fine with .python-version-default, and the changes .pre-commit-config.yml look good to me. if @jaimergp is okay with it, let's merge. 🚀

[trallard]

Ok will merge.

[peytondmurray]

Closes #842.