Whenever a new version is released, I read its What's New documentation.
Beyond that, I like to read source code, both for the stdlib and popular third-party packages. This advice generally applies when I'm learning any new language or re-familiarizing myself with one, not just Python.
I really enjoyed Fluent Python a while back as an intermediate book.
Python official docs are not completely horrible, but compared to most other popular languages (Kotlin, Scala, Rust, Go at least), the Python official docs are kind of meh.
I suppose Python docs beat C and C++ which do not have official docs besides the spec. (not counting K&R and Bjarne's books).
Also I guess Javascript does not have official docs (ie MDN is not official)
https://docs.python.org/3/tutorial/index.html
https://docs.python.org/3/library/index.html
Whenever a new version is released, I read its What's New documentation.
Beyond that, I like to read source code, both for the stdlib and popular third-party packages. This advice generally applies when I'm learning any new language or re-familiarizing myself with one, not just Python.