Require minimum Python version

setup.cfg allows fine-grained control of which Python versions are supported. We assume that setup.py is like:

from setuptools import setup; setup()

and then the minimum Python version in setup.cfg:

[options]
python_requires = >= 3.7

Install development packages (those that you don’t want a fixed static copy of) by:

pip install -e .

Related: Minimal setup.py and setup.cfg