Mercurial is a distributed open source source control (also known as "version control") system for tracking and handling file modifications. Mercurial can be used as the version control system for Python projects.
The official Mercurial tutorial goes through the basics. It has great examples for syntax and expected output.
Mercurial: The Definitive Guide is a free online version of the O'Reilly book.
Monoroke is a Mercurial server written in Rust designed to be used for very large monorepos that have thousands of commits affecting millions of files per hour.
Fix errors in your Python code before your users see them by monitoring with Rollbar.
Deploy web apps with the Ansible configuration management tool.
Build microservices with Docker, Flask & React in this great course.