I just stumbled across this when looking for something else. It looks very interesting
A pure-Python desktop application and library for chemistry and cheminformatics — molecular visualization, SMILES parsing, PDB loading, MMFF94 geometry optimization, descriptors, and a plugin ecosystem. Minimum dependencies. Everything implemented from scratch.
Looks to be a pretty comprehensive, cheminformatics, structure visualisation package. I have look in more detail later
Available on GitHub https://github.com/vijaymasand/PyChem-Pro
Detailed description here https://sites.google.com/view/pydescriptorcstar/pychem-pro