{* ../../docs_src/sub_applications/tutorial001_py39.py hl[3, 6:8] *}

### Unteranwendung { #sub-application }

Erstellen Sie dann Ihre Unteranwendung und deren *Pfadoperationen*.

Diese Unteranwendung ist nur eine weitere Standard-FastAPI-Anwendung, aber diese wird „gemountet“:

{* ../../docs_src/sub_applications/tutorial001_py39.py hl[11, 14:16] *}

{* ../../docs_src/sub_applications/tutorial001_py39.py hl[3, 6:8] *}

### Sub-application { #sub-application }

Then, create your sub-application, and its *path operations*.

This sub-application is just another standard FastAPI application, but this is the one that will be "mounted":

{* ../../docs_src/sub_applications/tutorial001_py39.py hl[11, 14:16] *}

{* ../../docs_src/background_tasks/tutorial001_py39.py hl[6:9] *}

## Добавление фоновой задачи { #add-the-background-task }

Внутри вашей функции‑обработчика пути передайте функцию задачи объекту фоновых задач методом `.add_task()`:

{* ../../docs_src/background_tasks/tutorial001_py39.py hl[14] *}

`.add_task()` принимает следующие аргументы:

from docs_src.python_types.tutorial005_py39 import get_items


def test_get_items():
    res = get_items(
        "item_a",
        "item_b",
        "item_c",
        "item_d",
        "item_e",
    )

from fastapi.testclient import TestClient
from inline_snapshot import snapshot

from docs_src.behind_a_proxy.tutorial004_py39 import app

client = TestClient(app)


def test_main():
    response = client.get("/app")
    assert response.status_code == 200
    assert response.json() == {"message": "Hello World", "root_path": "/api/v1"}


def test_openapi_schema():
    response = client.get("/openapi.json")

{* ../../docs_src/background_tasks/tutorial001_py39.py hl[6:9] *}

## Add the background task { #add-the-background-task }

Inside of your *path operation function*, pass your task function to the *background tasks* object with the method `.add_task()`:

{* ../../docs_src/background_tasks/tutorial001_py39.py hl[14] *}

`.add_task()` receives as arguments:

{* ../../docs_src/background_tasks/tutorial001_py39.py hl[6:9] *}

## Adicione a tarefa em segundo plano { #add-the-background-task }

Dentro da sua *função de operação de rota*, passe sua função de tarefa para o objeto de *tarefas em segundo plano* com o método `.add_task()`:

{* ../../docs_src/background_tasks/tutorial001_py39.py hl[14] *}

O `.add_task()` recebe como argumentos:

from fastapi.testclient import TestClient

from docs_src.response_cookies.tutorial001_py39 import app

client = TestClient(app)


def test_path_operation():
    response = client.post("/cookie/")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Come to the dark side, we have cookies"}

from fastapi.testclient import TestClient

from docs_src.response_cookies.tutorial002_py39 import app

client = TestClient(app)


def test_path_operation():
    response = client.post("/cookie-and-object/")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Come to the dark side, we have cookies"}

from docs_src.app_testing.tutorial001_py39 import client, test_read_main


def test_main():
    test_read_main()


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/": {
                "get": {