Add data_files support in setup.cfg

[ssato]

Summary of changes

These commits add data_files support in setup.cfg, discussed in the issue #1189, such like the following.

[options.data_files]
data = data/48x48/logo.png, data/scale/logo.svg
conf =
    site.d/00_default.conf
    host.d/00_default.conf

I think it may close #1189.

Pull Request Checklist

• Changes have tests
• News fragment added in changelog.d. See documentation for details

[pganssle]

I believe this is failing because dist.data_files gets parsed first to a dict (with arbitrary order on Py < 3.6), then turned into this key/value list thing.

I would look at what the other tests do, but I think a quick fix would be this:

expected = {
    'cfg': ['a/b.conf', 'c/d.conf'],
    'data': ['e/f.dat', 'g/h.dat']
}

with get_dist(tmpdir) as dist:
    # Order independent comparison
    assert dict(dist.data_files) == expected

[ssato]

Thanks a lot for your suggestion! I completely forgot about that. I'll commit the fix into this my branch.

[ssato]

I committed the fix based on your suggestion but data type of expected result is kept.

[pganssle]

I've rebased this branch against master and squashed together the fixup commits, plus touched up some of the commit messages and the changelog entry, so everything looks good to me.

Thanks @ssato for your PR!

[benoit-pierre]

The documentation should be updated.

[pganssle]

@benoit-pierre Good catch, I guess we need to add it to this table. Anywhere else?

[benoit-pierre]

Yes, and I would add a new column to the table mention the minimum supported version.

[pganssle]

@ssato If you want to update the documentation, please do a force-pull from your branch, since I've rewritten the PR's history since your last commit, and that will cause conflicts.

[ssato]

@ssato If you want to update the documentation, please do a force-pull from your branch, since I've rewritten the PR's history since your last commit, and that will cause conflicts.

@pganssle Thanks a lot for the cleanups! It looks much better ;-)
I'll not update my branch and keep as it is now, just wait for the merge.

[jaraco]

I think there's still an outstanding request to update the documentation. @ssato would you do that please?

[pganssle]

@jaraco @benoit-pierre Normally I'd block on getting an update, but given that we're doing a sprint this weekend, I'm tempted to just merge this as-is and leave the documentation update as an easy [good first issue].

If no one takes it at the sprints this weekend, I can do it myself on Monday, but frankly it's nice to have some very simple fixes that you can use as a demo PR for new contributors.

[jaraco]

Works for me. @pganssle Would you file that ticket?

[pganssle]

Filed #1522.

[dirk-thomas]

Since distutils on the very lowest level replaces - in keys with _ (https://github.com/python/cpython/blob/31ec52a9afedd77e36a3ddc31c4c45664b8ac410/Lib/distutils/dist.py#L414) this can't be used to install data files into a location which contains dashes.