You put it on top of a function. Like a pretty decorative hat (I guess that's where the term came from).

A "decorator" takes the function below and does something with it.

In our case, this decorator tells **FastAPI** that the function below corresponds to the **path** `/` with an **operation** `get`.

It is the "**path operation decorator**".

///

You can also use the other operations:

The *path operation decorator* receives an optional argument `dependencies`.

It should be a `list` of `Depends()`:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[19] *}

These dependencies will be executed/solved the same way as normal dependencies. But their value (if they return any) won't be passed to your *path operation function*.

/// tip

    response = client.get("/decorator-depends/?q=foo")
    assert response.status_code == 200
    assert response.json() == {"in": "decorator-depends"}


def test_decorator_depends_q_foo_skip_100_limit_200():
    response = client.get("/decorator-depends/?q=foo&skip=100&limit=200")
    assert response.status_code == 200
    assert response.json() == {"in": "decorator-depends"}


def test_router_depends():

/// info | Información sobre `@decorator`

Esa sintaxis `@algo` en Python se llama un "decorador".

Lo pones encima de una función. Como un bonito sombrero decorativo (supongo que de ahí viene el término).

Un "decorador" toma la función de abajo y hace algo con ella.

            session = verbose;
        }

        for (RepositorySessionDecorator decorator : decorators) {
            RepositorySystemSession decorated = decorator.decorate(project, session);
            if (decorated != null) {
                session = decorated;
            }
        }

        CollectRequest collect = new CollectRequest();

## `dependencies` zum *Pfadoperation-Dekorator* hinzufügen { #add-dependencies-to-the-path-operation-decorator }

Der *Pfadoperation-Dekorator* erhält ein optionales Argument `dependencies`.

Es sollte eine `list`e von `Depends()` sein:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[19] *}

 * CharEscaper based on the generated array.
 *
 * @author Sven Mawson
 * @since 15.0
 */
@GwtCompatible
public final class CharEscaperBuilder {
  /**
   * Simple decorator that turns an array of replacement char[]s into a CharEscaper, this results in
   * a very fast escape method.
   */
  private static final class CharArrayDecorator extends CharEscaper {

Dekoratörler, dekoratif bir şapka gibi (sanırım terim buradan geliyor) fonksiyonların üzerlerine yerleştirilirler.

Bir "dekoratör" hemen altında bulunan fonksiyonu alır ve o fonksiyon ile bazı işlemler gerçekleştirir.

Bizim durumumuzda, kullandığımız dekoratör, **FastAPI**'a altındaki fonksiyonun `/` yoluna gelen `get` metodlu isteklerden sorumlu olduğunu söyler.

///

## Create a middleware { #create-a-middleware }

To create a middleware you use the decorator `@app.middleware("http")` on top of a function.

The middleware function receives:

* The `request`.
* A function `call_next` that will receive the `request` as a parameter.

El decorador de *path operation* recibe un argumento opcional `dependencies`.

Debe ser una `list` de `Depends()`:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[19] *}

Estas dependencias serán ejecutadas/resueltas de la misma manera que las dependencias normales. Pero su valor (si devuelven alguno) no será pasado a tu *path operation function*.