🔧 MAINTAIN: Switch to declarative metadata

[hukkin]

I was testing out some tooling (setup-py-upgrade and setup-cfg-fmt) and came up with this auto-generated PR.

Declarative metadata has some advantages:

• Can be read by tooling without the need to execute arbitrary Python code
• Is easy for tools like setup-cfg-fmt to modify. Brings us automatic version classifiers, ordering, etc.
• No need for some boilerplate like the get_version function.

Maybe we want to keep metadata in setup.py for consistency with other projects though?

I kept a dummy setup.py as pip doesn't yet support editable installs for projects without one.

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Codecov Report

Merging #139 (7efdae9) into master (36c386d) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #139   +/-   ##
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  Coverage   96.32%   96.32%           
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  Files          72       72           
  Lines        3266     3266           
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  Hits         3146     3146           
  Misses        120      120           

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pytests	96.32% <ø> (ø)

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[chrisjsewell]

rather than installing setuptools, should it be defined in a pyproject.toml, e.g. https://github.com/aiidateam/aiida-core/blob/623d0d8b8b3f11e4f25a0d7d60061dccdba7150a/pyproject.toml#L1

this is the thing I don't like about this "new" setuptools system; you have to replace the single setup.py with three files to specify something I think should all be in pyproject.toml (https://discuss.python.org/t/where-to-get-started-with-pyproject-toml/4906/6)

[chrisjsewell]

see comment

[hukkin]

rather than installing setuptools, should it be defined in a pyproject.toml, e.g. https://github.com/aiidateam/aiida-core/blob/623d0d8b8b3f11e4f25a0d7d60061dccdba7150a/pyproject.toml#L1

So firstly, setuptools was already installed. The change made here merely updates it similar to what we do with pip because the version that was installed was affected by this setuptools issue which made the build fail when using the setup.cfg mechanism for reading __version__ from Python source. An up-to-date setuptools has this issue fixed.

Adding a pyproject.toml (thus activating PEP 517 build) and restricting setuptools version there would work as well yeah. This comes with the downside that we get yet another file as you mentioned 🤦 😄

this is the thing I don't like about this "new" setuptools system; you have to replace the single setup.py with three files to specify something I think should all be in pyproject.toml (https://discuss.python.org/t/where-to-get-started-with-pyproject-toml/4906/6)

Yeah its pretty annoying right now. With PEP 621 accepted I guess setuptools will soon support metadata in pyproject.toml but we're not there yet. Meanwhile we have a few options:

• dont change anything
• merge this PR (declarative metadata)
  • with or without pyproject.toml (i.e. with or without PEP517 builds)
  • with or without the empty setup.py (i.e. with or without pip install -e . support)
• dump setuptools and use another PEP517/pyproject.toml native build tool (flit, poetry)

[chrisjsewell]

Oh definitely sticking with setuptools, for editable install support, and because it is more well known for other contributors to work with.
Bit on the fence about the change, but if it is done at some stage I would certainly add the pyproject.toml build dependencies

[hukkin]

Oh definitely sticking with setuptools

👍

for editable install support, and because it is more well known for other contributors to work with.

The other two tools have editable installs, so its not that bad, just not via pip.

Bit on the fence about the change, but if it is done at some stage I would certainly add the pyproject.toml build dependencies

Added the pyproject.toml

[chrisjsewell]

Both mypy and flake8 configuration can be moved to setup.cfg, which might be desirable to reduce the number of files:

• https://flake8.pycqa.org/en/latest/user/configuration.html
• https://mypy.readthedocs.io/en/stable/config_file.html

[chrisjsewell]

add a comment that this is required only for editable builds

[hukkin]

added

[hukkin]

Moved mypy and flake8 conf to setup.cfg