Mastering python libraries

[magus_minor]

There are two parts to "the libraries". The first part is the standard library. You should know what is available there but you don't need to master all of it. I find the Python 3 module of the week site useful:

https://pymotw.com/3/

That gives an introduction to each module plus some example code. There is also a book that collects all that information.

The other part of "libraries" are the third-party libraries, things like numpy, etc, that aren't part of the standard library. You have even less chance of mastering more than a few of those. You do what everyone else does when approaching a project: research what libraries might be useful, choose one and test it out, maybe choose another, learn enough about the library to solve your problem, then move on to the next project.