Drop python 3.6 support

[tk0miya]

Feature or Bugfix

• Refactoring

Purpose

• Based on our "Python version support policy", python3.6 support will be ended at 2023.04.
• This drops the support from the master branch used for development for v6.0.
• I'll also drop python 3.7 support on the next PR.
• This only drops the code for py36. It would be better to refactor with new syntax, libraries and so on after clean up.

[tk0miya]

Note: Ubuntu-20.04 distributes docutils-0.16. So it will be the new supported base version. I'll work on it after merging this.
https://packages.ubuntu.com/focal/python3-docutils

[AA-Turner]

Would it be possible to increase the minimum requirement to Docutils 0.18? There are lots of patches in Sphinx for Docutils 0.17 or earlier, and it would be nice to remove those at the same time as we drop end-of-life Python versions.

As far as I can tell the current Sphinx version support policy only makes reference to Ubuntu for Python versions, not for Docutils.

A

[tk0miya]

In my thought, it's simple to refer to Ubuntu LTS to decide the version of dependencies. I feel dropping dependency does not help our work. So -0 for your proposal

[AA-Turner]

I feel dropping dependency does not help our work.

We could take a view to support every version of Python / Docutils perpeptually, and just accumulate a lot of patches. I personally find it harder to reason about the code when there are multiple layers of patches etc, especially ones that monkeypatch Docutils, hence looking to bump the version higher and remove code.

I'd argue we should look to make things simpler for ourselves as maintainers where possible - Ubuntu is a re-distributor and will cope with decisions that we make under their policies, but I don't think we should be somewhat arbitrarily bound by them when there are significant code simplifications from the bump to 0.18.

A

[tk0miya]

Does this conflict with #10470? May I merge this?

[AA-Turner]

Does this conflict with #10470? May I merge this?

It probably does, but I'd say merge this first and then I'll deal with the conflicts and rebase #10470.

A

[danieleades]

you might want to consider running pyupgrade over these deprecation PRs

https://pypi.org/project/pyupgrade/

[AA-Turner]

I ran pyupgrade locally on my larger refactoring branch (https://github.com/AA-Turner/sphinx/commits/drop-py37-refactoring) -- this should probably stay more focussed.

A

[AA-Turner]

I will rebase #10470 on master.

A