Learn the magic of writing Python code that monitors, alters and reacts to module imports, changes to variables, calls to functions and invocations of the builtins. Learn how to slide a class underneath a module to intercept reads/writes, place automatic type checking over your object attributes and use stack peeking to make selected attributes private to their owning class. We'll cover import hacking, metaclasses, descriptors and decorators and how they work internally.