If you need to mark a function, a class or a method as deprecated, you can use the @deprecated decorator.
This documentation explains how to install and use the Python-Deprecated library.
It includes a detailed tutorial and simple use cases.
You will also have all the keys to contribute to the development of the source code.

Why should you pay for this documentation? This a way to donate to the Python-Deprecated project.
Your gratitude and financial help will be motivating to continue the project's development.