Ask HN: How to develop multiple interdependent Python packages in 2021?

What I'm looking for: - Developing multiple Python packages in tandem - The packages have interdependencies among themselves - Will publish to PyPI (or Conda) for easy install - All code is pure Python - No complex build step for any of the packages - Willing to use something like poetry as long as package users don't have to use poetry themselves - Separate testing environments for the different packages

Any input/utorials/docs/blog posts/tools/sample repositories would be appreciated.