Lesson 14 — Decorators

Wrapping functions

A decorator is a function that takes another function and returns a new one that adds behaviour around it — logging, timing, checks. Writing @name on the line above a def is a shortcut for name = deco(name). The original function still runs inside the wrapper.

@timer
def build():
    ...
# same as: build = timer(build)

Why it matters: frameworks use decorators everywhere, for example to mark a function as a web route.