Using RASA from python

Hey community! I see rather detailed instructions on how to use RASA from CLI but as far as I understand, it’s possible to use RASA from python (like this repo shows: https://github.com/nahidalam/customer_bot). However I see only short specs in Code reference section:

These specs don’t provide any usage examples and it’s hard for me to get the idea of how to use RASA from Python to train, test, inference model, work with trackers and etc. Are there any detailed docs / explanations / tutorials? Or any detailed example projects (even if they are not up-to-date)?