Modern Flask, Quart, and many lightweight Python backends rely on Jinja2 for templating. But a lot of developers come in with a Django mindset—and sometimes that mindset breaks their templates in very loud, very unhelpful ways.

Decorators in Python are a powerful way to modify or extend the behavior of functions or classes without permanently modifying them. They are often used for logging, access control, memoization, etc. In this guide, we'll explore how to use decorators in classes, including both class- and function-based decorators, with and without arguments.