Type Aliases & NewType

Complex type expressions repeat across signatures and turn into noise fast. A dict[str, list[tuple[int, float]]] parameter type tells the reader almost nothing about what's in there. Type aliases give that shape a readable name, and NewType goes one step further by creating distinct types that the checker treats as separate, even when they share a runtime representation. This lesson covers the four ways to name a type in modern Python and the one tool that turns same-looking primitives into checkable, distinct identities.