`ModuleNotFoundError: distutils` on Python 3.12

[kdeldycke]

distutils has been removed in the upcoming Python 3.12.

So the Python 3.12.0-alpha.7 version I am trying, I get the following traceback:

(...)
  File ".../python3.12/site-packages/pytest_cases/common_pytest_marks.py", line 8, in <module>
    from distutils.version import LooseVersion
ModuleNotFoundError: No module named 'distutils'

Source: https://github.com/kdeldycke/click-extra/actions/runs/5061009247/jobs/9086125761#step:7:76

[smarie]

Thanks a lot @kdeldycke ! It seems that we should instead try

from pkg_resources import parse_version

(other possibilities are discussed in https://stackoverflow.com/questions/11887762/how-do-i-compare-version-numbers-in-python but they seem a bit more risky to me)

[mportesdev]

Tried with Python 3.12.0b2:

$ python -c 'from distutils.version import LooseVersion; print(LooseVersion("10.0.0") > LooseVersion("2.10.0"))'
...
ModuleNotFoundError: No module named 'distutils'

A quick fix would be to install setuptools. The import will work with the following deprecation message:

$ pip install setuptools
...
Successfully installed setuptools-67.8.0
$ python -c 'from distutils.version import LooseVersion; print(LooseVersion("10.0.0") > LooseVersion("2.10.0"))'
<string>:1: DeprecationWarning: distutils Version classes are deprecated. Use packaging.version instead.
True

Using the packaging library seems to work, too:

$ pip install packaging
...
Successfully installed packaging-23.1
$ python -c 'from packaging.version import Version; print(Version("10.0.0") > Version("2.10.0"))'
True

[shaunc]

Already causing a deprecation warning in python 3.11:

06/15/23 21:12:24] WARNING  /home/shauncutts/.cache/pypoetry/virtualenvs/moonshine-CuQK1AVF-py3.11/lib/python3.11/site-packages/pytest_cases/com warnings.py:109
                             mon_pytest_marks.py:30: DeprecationWarning: distutils Version classes are deprecated. Use packaging.version instead.                
                               PYTEST_VERSION = LooseVersion(pytest.__version__)                                                                                 
                                                                                                                                                                 
                    WARNING  /home/shauncutts/.cache/pypoetry/virtualenvs/moonshine-CuQK1AVF-py3.11/lib/python3.11/site-packages/pytest_cases/com warnings.py:109
                             mon_pytest_marks.py:31: DeprecationWarning: distutils Version classes are deprecated. Use packaging.version instead.                
                               PYTEST3_OR_GREATER = PYTEST_VERSION >= LooseVersion('3.0.0')                                                                      

[jayqi]

@smarie Will this be addressed soon? The release candidate for Python 3.12 was published last week, and the planned release for Python 3.12 is in less than 2 months. I would like to start including Python 3.12 in my test matrix.

Also, I don't think pkg_resources.parse_version is the right solution. The pkg_resources package has a notice that it is deprecated. The deprecation warnings about distutils recommend using packaging.version, which @mportesdev demonstrated above to work as expected.

[guidovanschie-nedap]

https://peps.python.org/pep-0632/#migration-advice

For these modules or types, use the standards-defined Python Packaging Authority packages specified:

distutils.version — use the packaging package

[jayqi]

@smarie Python 3.12 is officially released today, and pytest-cases is incompatible. It would be great if one of either #312 or #303 were adopted to fix this.