The Python security best practices cheat sheet provides guidance for developers to maintain Python code security. It covers various aspects such as sanitizing external data, scanning your code, being careful when downloading packages, reviewing dependency licenses, using virtual environments, setting DEBUG = False in production, and being cautious with string formatting and serialization. The cheat sheet emphasizes the importance of assuming malicious packages exist in PyPI, using tools like Snyk Advisor to check package security, and leveraging type annotations for better code quality and security.