Tool or way to support handling dependencies of modules in various platforms (for machine learning in Python)
Python is notoriously painful when it comes to dependency and version management.

I think its your job to make a portable application, and there are usually methods to do so (even if they  boil down to ugly branching logic based on the host OS type/etc).  Most of the time, you can avoid OS specific things with some effort though.

In terms of deploying code to clients, I would recommend looking at tools that bundle your code into a stand-alone application (pyinstaller, py2app, etc).  If you can build a standalone app for your clients for each OS, you won't have to worry about what is on their system (python versions, docker, etc).