Generic Types

Generics let you write a function or class once and have the type checker carry the element type through every call. The payoff is real: a single Repository class can serve products, orders, and customers without losing type information, and a single first helper can return a Product to one caller and a Customer to another with no casts. This lesson covers TypeVar, generic functions, generic classes, bounded and constrained type variables, variance basics, and the new PEP 695 syntax that ships with Python 3.12.