# Lecture 6: Decorators and the @ syntax

**English** · [Dansk](Lecture-6-Decorators-da) · [Bahasa Malaysia](Lecture-6-Decorators-ms)

![Lecture 6: Decorators and the @ syntax](https://git.tirsystem.com/Tirsvad-Udemy-100-days-of-code/054-flask/raw/branch/main/docs/images/lecture-06.png)

## What the lecture covers

A decorator adds behaviour to an existing function without editing it. The lecture first recaps first-class functions, nesting and returning functions, then introduces the `@` syntax: writing `@make_bold` above a function is the same as `say_hello = make_bold(say_hello)`. Flask uses the same idea for its routes: `@app.route("/")`. With `functools.wraps` the wrapped function keeps its name.

## What we gained

- The `@` syntax as shorthand for passing a function to a wrapper.
- Stacking decorators: the one nearest the function runs first, so `@make_bold @make_emphasis @make_underlined` gives `<b><em><u>...</u></em></b>`.
- An understanding of what `@app.route("/")` does in the next lectures.

## In this repository

Code: `src/flask_day_54/domain/decorators.py`. Tests: `tests/unit/test_decorators.py`.