In this talk, we’ll explore the weird and wonderful world of the double-underscore, and find out how dunders can be useful, silly, dangerous, and just fun! We’ll play pranks on Python’s builtin operators for arithmetic and comparison. We’ll make arbitrary objects behave like dictionaries and containers. We’ll reduce an object’s memory usage, and speed up tests for membership. We’ll even try some naughty function hacks that we should never use in real life!