built in

Python Module Index

The latest version of Python has over 300 built in modules.

The list, from the docs, is here: https://docs.python.org/3/py-modindex.html

These are continuously evolving as the ecosystem changes, so some packages are added over time whilst others are depreciated. The evolution is the main reason that modularised languages, like Python, have survived. They simply adapt to fit the current market criteria and requirements.

Even a very complete (expert) coder will not have used all of the built in modules, so the expertise is to understand what is generally available from the already massive resource.