**FastAPI** knows what to do in each case and how to reuse the same object, so that all the background tasks are merged together and are run in the background afterwards:


{* ../../docs_src/background_tasks/tutorial002_an_py310.py hl[13,15,22,25] *}


In this example, the messages will be written to the `log.txt` file *after* the response is sent.

If there was a query in the request, it will be written to the log in a background task.

O **FastAPI** sabe o que fazer em cada caso e como reutilizar o mesmo objeto, de forma que todas as tarefas em segundo plano sejam combinadas e executadas em segundo plano depois:


{* ../../docs_src/background_tasks/tutorial002_an_py310.py hl[13,15,22,25] *}

Neste exemplo, as mensagens serão escritas no arquivo `log.txt` *após* o envio da resposta.

Se houver uma query na request, ela será registrada em uma tarefa em segundo plano.

* `Depends`
* `Security`
* `Cookie`
* `Header`
* `Path`
* `Query`

Они работают так же, как и в других FastAPI эндпоинтах/*операциях пути*:

{* ../../docs_src/websockets/tutorial002_an_py310.py hl[68:69,82] *}

/// info | Примечание

В веб-сокете вызывать `HTTPException` не имеет смысла. Вместо этого нужно использовать `WebSocketException`.

**FastAPI** sabe qué hacer en cada caso y cómo reutilizar el mismo objeto, de modo que todas las tareas en segundo plano se combinan y ejecutan en segundo plano después:

{* ../../docs_src/background_tasks/tutorial002_an_py310.py hl[13,15,22,25] *}

En este ejemplo, los mensajes se escribirán en el archivo `log.txt` *después* de que se envíe el response.

Si hay un query en el request, se escribirá en el log en una tarea en segundo plano.

* `Depends`
* `Security`
* `Cookie`
* `Header`
* `Path`
* `Query`

They work the same way as for other FastAPI endpoints/*path operations*:

{* ../../docs_src/websockets/tutorial002_an_py310.py hl[68:69,82] *}

/// info

As this is a WebSocket it doesn't really make sense to raise an `HTTPException`, instead we raise a `WebSocketException`.

@pytest.fixture(
    name="mod",
    params=[
        pytest.param("tutorial004_py39"),
        pytest.param("tutorial004_py310", marks=needs_py310),
        pytest.param("tutorial004_an_py39"),
        pytest.param("tutorial004_an_py310", marks=needs_py310),
    ],
)
def get_mod(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.security.{request.param}")

    return mod

@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial002_py39"),
        pytest.param("tutorial002_py310", marks=needs_py310),
        pytest.param("tutorial002_an_py39"),
        pytest.param("tutorial002_an_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    clear_sqlmodel()
    # TODO: remove when updating SQL tutorial to use new lifespan API