Add auto-publish to PyPI

[nikhilwoodruff]

Following up on a call recently where there were some issues with pip installing, I thought I'd just file a PR here if it's useful. This is basically Jason's PR but with the extra step of an auto-publish action on the master branch. I think the only thing needed would be to make sure PSLmodels has an organisation secret called PYPI which is a token exported from the pypi.org account.

@jdebacker @rickecon @jpycroft FYI

[codecov-commenter]

Codecov Report

Merging #795 (5854b88) into master (8ce4f4e) will not change coverage.
The diff coverage is n/a.

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  Coverage   86.32%   86.32%           
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  Files          40       40           
  Lines        6318     6318           
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  Hits         5454     5454           
  Misses        864      864           

Flag	Coverage Δ
unittests	86.32% <ø> (ø)

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[rickecon]

@nikhilwoodruff and @jdebacker. Should we update the Python version in line 21 and line 50 from 3.7 to 3.9?

[jdebacker]

@rickecon I don't think it matters - that's just the version of Python used to build the package - not the version of Python the package is compatible with.

[rickecon]

@nikhilwoodruff. I don't see anywhere this automatically updates the version number. I like your CHANGELOG.md approach in OpenFisca-UK. Can we add that to this PR, if @jdebacker and @rickecon create the appropriate CHANGELOG.md file and add it to your branch via PR?

[jdebacker]

@rickecon I'd propose we leave the automatic version numbering for a separate PR. I could see cases where there is e.g., a small fix of a typo in the documentation - does that deserve a new version/package? With the skip_existing: true in the GH Action to publish, no new package will be uploaded to PyPI unless there is a version number change. So we might role with the auto publish as setup here for a bit and see how it works, then decide to adopt the auto version numbering. Does that sound like a plan?

cc @nikhilwoodruff

[nikhilwoodruff]

Yeah, thanks both, I agree @jdebacker - plus, I just realised that the auto-changelog bumper needs another Github token setup, which complicates it slightly (right now, I think all version bumps on policyengine repos are all in my name).

[rickecon]

OK. Then I think this PR is ready. @jdebacker are you good?

[jdebacker]

Thanks @nikhilwoodruff !