Use `pyproject.toml` instead of `setup.cfg` and `setup.py`

[mbalatsko]

I suggest upgrading the project structure to a more modern python package format using pyproject.toml. I could gladly get it done, if you agree @raimon49. But I wanted to clarify some things first:

• Is it a hard requirement for the package to have pip-compile as the packaging manager? Poetry seems to be able to handle all transitive dependencies properly and does not require exact versions specified, it works well with version bounds. For downstream packages, == in requirements could become substantial issue
• Are you ok with having version, author, etc. only in pyproject.toml?

[stefan6419846]

pip-tools, where pip-compile is part of, is just used for having a known set of fixed versions. The packaging backend already is setuptools and the versions are not really fixed inside the configuration file (although I am not sure why pytest-runner would be required for building the package itself): https://github.com/raimon49/pip-licenses/blob/b3a3d8739e2b725e39d142283d66d0c5f320b3d4/setup.cfg#L27-L37

[raimon49]

Thanks for the suggestion, I also worked on another project to migrate to pyproject.toml but stopped halfway. At that time, I selected setuptools>=61.0, build_meta as build-backend.

The main toolchain used in this project is as commented by @stefan6419846 . I know that tools like Pipenv and Poetry have appeared, but I am still using pip-tools+venv. The Makefile for this project describes the main tasks for the release.

In moving to pyproject.toml, I have no problem if metadata such as version, author, classifiers are written only in pyproject.toml.