Sort the return value of `python_versions`

[angelo-peronio]

How would this feature be useful?

If called with max_version=None, python_versions returns a list of versions read from the Trove classifiers. I propose to sort that list before returning it, so that the oldest supported Python version is python_versions()[0], and the most recent one python_versions()[-1].

Describe the solution you'd like

For instance:

from packaging.version import Version

then this line

nox/nox/project.py

Line 124 in 5a90136

return from_classifiers

becomes

    return sorted(from_classifiers, key=Version)

Describe alternatives you've considered

Of course, any sane pyproject.toml will have the classifiers already sorted, but should we rely on common sense?

Anything else?

I can prepare a pull request.

[henryiii]

I think we could have a sort=True parameter. The reason it's better than sorted(...) directly is that we can pick off the version and sort that in order. Though, now that we are moving to 3.10+, it always would be in order with a simple sort, so maybe it's not that important anymore?

[angelo-peronio]

The reason it's better than sorted(...) directly is that we can pick off the version and sort that in order.

I am not able to follow your reasoning. Could you oversimplify it for me?