pkg_resources: Correctly handle normalized project names

[di]

Summary of changes

This fixes an issue where pkg_resources.require treats project names with periods differently than other project names.

Before:

>>> import pkg_resources
<stdin>:1: DeprecationWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html
>>> pkg_resources.require('zip-po')
[zip-po 0.0.0 (/home/di/.pyenv/versions/3.12.4/lib/python3.12/site-packages)]
>>> pkg_resources.require('zip_po')
[zip-po 0.0.0 (/home/di/.pyenv/versions/3.12.4/lib/python3.12/site-packages)]
>>> pkg_resources.require('zip.po')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/di/git/pypa/setuptools/pkg_resources/__init__.py", line 1061, in require
    needed = self.resolve(parse_requirements(requirements))
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/di/git/pypa/setuptools/pkg_resources/__init__.py", line 888, in resolve
    dist = self._resolve_dist(
           ^^^^^^^^^^^^^^^^^^^
  File "/home/di/git/pypa/setuptools/pkg_resources/__init__.py", line 929, in _resolve_dist
    raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'zip.po' distribution was not found and is required by the application

After:

>>> import pkg_resources
<stdin>:1: DeprecationWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html
>>> pkg_resources.require('zip-po')
[zip-po 0.0.0 (/home/di/.pyenv/versions/3.12.4/lib/python3.12/site-packages)]
>>> pkg_resources.require('zip_po')
[zip-po 0.0.0 (/home/di/.pyenv/versions/3.12.4/lib/python3.12/site-packages)]
>>> pkg_resources.require('zip.po')
[zip-po 0.0.0 (/home/di/.pyenv/versions/3.12.4/lib/python3.12/site-packages)]

The simplest fix would be a one-character update to safe_name, which currently does not normalize periods when producing a "safe" project name:

setuptools/pkg_resources/__init__.py

Lines 1551 to 1556 in 56c055b

	def safe_name(name: str) -> str:
	"""Convert an arbitrary string to a standard distribution name
	Any runs of non-alphanumeric/. characters are replaced with a single '-'.
	"""
	return re.sub('[^A-Za-z0-9.]+', '-', name)

However, since this is a public API, changes here might be more disruptive, so I opted to change pkg_resources usage of safe_name internally instead.

Closes #4853.

Pull Request Checklist

• Changes have tests
• News fragment added in newsfragments/.
  (See documentation for details)

[abravalheri]

Thank you very much @di for having a look on this.

I was working on a regression test.
Would you consider adding the following to the test_pkg_resources?

import inspect

# ...

class TestWorkdirRequire:
    def fake_site_packages(self, tmp_path, monkeypatch, dist_files):
        site_packages = tmp_path / "site-packages"
        site_packages.mkdir()
        for file, content in self.FILES.items():
            path = site_packages / file
            path.parent.mkdir(exist_ok=True, parents=True)
            path.write_text(inspect.cleandoc(content), encoding="utf-8")

        monkeypatch.setattr(sys, "path", [site_packages])
        return os.fspath(site_packages)

    FILES = {
        "pkg1_mod-1.2.3.dist-info/METADATA": """
            Metadata-Version: 2.4
            Name: pkg1.mod
            Version: 1.2.3
            """,
        "pkg2.mod-0.42.dist-info/METADATA": """
            Metadata-Version: 2.1
            Name: pkg2.mod
            Version: 0.42
            """,
        "pkg3_mod.egg-info/PKG-INFO": """
            Name: pkg3.mod
            Version: 1.2.3
            """,
        "pkg4.mod.egg-info/PKG-INFO": """
            Name: pkg4.mod
            Version: 0.42
            """,
    }

    @pytest.mark.parametrize(
        ("name", "version", "req"),
        [
            ("pkg1.mod", "1.2.3", "pkg1.mod>=1"),
            ("pkg2.mod", "0.42", "pkg2.mod>=0.4"),
            ("pkg3.mod", "1.2.3", "pkg3.mod<=2"),
            ("pkg4.mod", "0.42", "pkg4.mod>0.2,<1"),
        ],
    )
    def test_require_normalised_name(self, tmp_path, monkeypatch, name, version, req):
        # https://github.com/pypa/setuptools/issues/4853
        site_packages = self.fake_site_packages(tmp_path, monkeypatch, self.FILES)
        ws = pkg_resources.WorkingSet([site_packages])

        [dist] = ws.require(req)
        assert dist.version == version
        assert dist.project_name == name
        assert os.path.commonpath([dist.location, site_packages]) == site_packages

[abravalheri]

@krpatter-intc, would you be able to test if this PR solves your problem?

I believe that can use "setuptools @ https://github.com/di/setuptools/archive/refs/heads/fix/4853.zip" (or some variation of this) in your pyproject.toml to download the version in this PR.

If it does not work, could you then please have a look on #4856 ("setuptools @ https://github.com/abravalheri/setuptools/archive/refs/heads/issue-4853.zip")?

[krpatter-intc]

@krpatter-intc, would you be able to test if this PR solves your problem?

Yep, I can confirm this fixes pkg_resources.require to take any format from the test package I built (and confirmed it was built/installed using the 75.8.1 release):

>>> pkg_resources.require("sample.module_under")
[sample-module-under 1 (c:\temp\example\.venv\lib\site-packages)]
>>> pkg_resources.require("sample-module_under") 
[sample-module-under 1 (c:\temp\example\.venv\lib\site-packages)]
>>> pkg_resources.require("sample-module-under") 
[sample-module-under 1 (c:\temp\example\.venv\lib\site-packages)]
>>>

Thanks for the quick turnaround!

EDIT: For clarity, this was done using:

https://github.com/di/setuptools/archive/refs/heads/fix/4853.zip

[abravalheri]

Thank you very much @krpatter-intc.

My initial idea was to go with this PR, but there are some tests failing, so we might go instead with #4856 (I think it will also solve your problem).