The setuptools page states that the use of pkg_resources is deprecated.

This can lead to warnings like:

It seems the package is only imported for using parse_version. In the same setuptools page, they suggest:

[...] Some useful APIs are also provided by packaging (e.g. requirements and version parsing). [...]

So in order to avoid this warnings (and possibly future failures), parse_version should be replaced by its packaging alternative.

The packaging package is already installed with test dependencies so it will not add any new extra "weight", but it should be added explicitly to the setup.py file.