title: Python: Multiple packages in one repository or one package per repository?
body: <p>I have a big Python 3.7+ project and I am currently in the process of splitting it into multiple packages that can be installed separately. My initial thought was to have a single Git repository with multiple packages, each with its own setup.py. However, while doing some research on Google, I found people suggesting one repository per package: (e.g., <a href="https://stackoverflow.com/questions/44020652/python-setuptools-working-on-two-dependent-packages-in-a-single-repo">Python - setuptools - working on two dependent packages (in a single repo?)</a>). However, nobody provides a good explanation as to why they prefer such structure. </p>
  
  <p>So, my question are the following: </p>
  
  <ul>
  <li>What are the implications of having multiple packages (each with its own setup.py) on the same GitHub repo?</li>
  <li>Am I going to face issues with such a setup? </li>
  <li>Are the common Python tools (documentation generators, pypi packaging, etc) compatible with with such a setup?</li>
  <li>Is there a good reason to prefer one setup over the other?</li>
  <li>Please keep in mind that this is not an opinion-based question. I want to know if there are any technical issues or problems with any of the two approaches.</li>
  </ul>
  
  <p>Also, I am aware (and please correct me if I am wrong) that setuptools now allow to install dependencies from GitHub repos, even if the GitHub URL of the setup.py is not at the root of the repository.</p>