The official Python documentation is excellent, and in many ways goes beyond providing just a list of existing modules and what they do. Sometimes if I'm bored I'll actually just pull up documentation for something I'm not 100% familiar with and have a look around, and I almost always find something new and useful. A couple of interesting ones are [0][1], and [2] is a nice starting point for discovering more. Not everyone's cup of tea, but I also found it enjoyable dive into asyncio with the docs.

[0] https://docs.python.org/3/howto/descriptor.html [1] https://docs.python.org/3/library/collections.html [2] https://docs.python.org/3/

I recommend any of the talks by James Powell at PyData. For example this one https://youtu.be/cKPlPJyQrt4

Edit: maybe this one on Numpy may be more relevant: https://youtu.be/u2yvNw49AX4