Modules and functions

Question

How do we know what are the modules and the functions that are defined in that module

Answer 1

Seek documentation! Often it will be installed with the module (although it may need an extra step), or ask your friendly neighborhood search engine (most major modules have pages out there).

If it's a smaller one, the reach out to where you got it, and ask for the API. If they want their stuff yes, they should have one.

Answer 2

If you need to install a module this's the documentation:
https://docs.python.org/3/installing/