setuptools provides, as is often used, a way to specify optional dependencies with extras_require. Is there a way to do the opposite? That is, to have
pip install mypackage install a full set of dependencies, but to have something like
pip install mypackage[core] or
pip install --core-option mypackage only install a limited set of core dependencies? It doesn’t have to be like extras_require, just some way to specify in the pip install that only core dependencies are required.
(For some packages, breaking backwards compatibility in terms of installation is a difficult choice, especially when most users want all of the dependencies. Nevertheless, some users can need to avoid heavy or broken dependencies that are not required for core functions.)
