I use Python3 more after reading the book:
Think Python
How to Think Like a Computer Scientist
Version 2.0.17
Allen Downey
and read the official Python document (it provides downloadable files in epub, pdf, html, you can download and read offline).
Sometimes I read Python standard library (module) to see how they code.
On Termux I copy the entire Python dir to phone memory to be viewed easily with CodeEditor.
To know where the lib dir is:
python3 -m site
Now simply exit python3 back to termux, then copy the entire dir to phone memory to read its core modules.
cp /data/data/com.termux/files/usr/lib/python3.9 ~/storage/shared/
Can start to read the module string.py
Another way to improvw your coding knowledge is to read other well-known projects. Here is a post, mentioned it more details https://www.cbui.dev/how-to-rapidly-improve-at-any-programming-language
It short: the article above mentioned the idea: learning by reading closed PRs of popular git projects. See the comments of knowledgeable maintainers and the diff history.