{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Ajouter une tâche d'arrière-plan

Dans votre *fonction de chemin*, passez votre fonction de tâche à l'objet de type `BackgroundTasks` (`background_tasks` ici) grâce à la méthode `.add_task()` :


{* ../../docs_src/background_tasks/tutorial001.py hl[14] *}

`.add_task()` reçoit comme arguments :

{* ../../docs_src/path_params_numeric_validations/tutorial002.py hl[7] *}

Mais gardez à l'esprit que si vous utilisez `Annotated`, vous n'aurez pas ce problème, cela n'aura pas d'importance car vous n'utilisez pas les valeurs par défaut des paramètres de fonction pour `Query()` ou `Path()`.

{* ../../docs_src/path_params_numeric_validations/tutorial002_an_py39.py hl[10] *}

## Ordonnez les paramètres comme vous le souhaitez (astuces)

```Python hl_lines="2  6-38  41-43"
{!../../docs_src/websockets/tutorial001.py!}
```

## Criando um `websocket`

Em sua aplicação **FastAPI**, crie um `websocket`:

{*../../docs_src/websockets/tutorial001.py hl[46:47]*}

/// note | Detalhes Técnicos

Você também poderia usar `from starlette.websockets import WebSocket`.

First, write all your **FastAPI** application as normally:

{* ../../docs_src/extending_openapi/tutorial001.py hl[1,4,7:9] *}

### Generate the OpenAPI schema

Then, use the same utility function to generate the OpenAPI schema, inside a `custom_openapi()` function:

{* ../../docs_src/extending_openapi/tutorial001.py hl[2,15:21] *}

### Modify the OpenAPI schema

Let's see the previous example again:

{* ../../docs_src/response_status_code/tutorial001.py hl[6] *}

`201` is the status code for "Created".

But you don't have to memorize what each of these codes mean.

You can use the convenience variables from `fastapi.status`.

{* ../../docs_src/response_status_code/tutorial002.py hl[1,6] *}

Nesse caso, o caminho original `/app` seria servido em `/api/v1/app`.

Embora todo o seu código esteja escrito assumindo que existe apenas `/app`.

{* ../../docs_src/behind_a_proxy/tutorial001.py hl[6] *}

{* ../../docs_src/async_tests/test_main.py hl[7] *}

/// tip | "Tipp"

Beachten Sie, dass die Testfunktion jetzt `async def` ist und nicht nur `def` wie zuvor, wenn Sie den `TestClient` verwenden.

///

Dann können wir einen `AsyncClient` mit der App erstellen und mit `await` asynchrone Requests an ihn senden.

{* ../../docs_src/async_tests/test_main.py hl[9:12] *}

Das ist das Äquivalent zu:

```Python

{* ../../docs_src/async_tests/test_main.py hl[7] *}

/// tip

Note that the test function is now `async def` instead of just `def` as before when using the `TestClient`.

///

Then we can create an `AsyncClient` with the app, and send async requests to it, using `await`.

{* ../../docs_src/async_tests/test_main.py hl[9:12] *}

This is the equivalent to:

```Python

{* ../../docs_src/first_steps/tutorial001.py hl[7] *}

Jest to funkcja Python.

Zostanie ona wywołana przez **FastAPI** za każdym razem, gdy otrzyma żądanie do adresu URL "`/`" przy użyciu operacji `GET`.

W tym przypadku jest to funkcja "asynchroniczna".

---

Możesz również zdefiniować to jako normalną funkcję zamiast `async def`:

{* ../../docs_src/first_steps/tutorial003.py hl[7] *}

/// note

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[48:55] hl[51:52,54] *}

### Read One Hero

We can **read** a single `Hero`.

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[58:63] hl[60] *}

### Delete a Hero

We can also **delete** a `Hero`.

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[66:73] hl[71] *}

### Run the App

You can run the app: