{* ../../docs_src/path_params/tutorial003_py39.py hl[6,11] *}

De lo contrario, el path para `/users/{user_id}` también coincidiría para `/users/me`, "pensando" que está recibiendo un parámetro `user_id` con un valor de `"me"`.

De manera similar, no puedes redefinir una path operation:

{* ../../docs_src/path_params/tutorial003b_py39.py hl[6,11] *}

from fastapi.testclient import TestClient

from docs_src.custom_response.tutorial009c_py39 import app

client = TestClient(app)


def test_get():
    response = client.get("/")

from docs_src.generate_clients import tutorial003_py39


def test_remove_tags(tmp_path: pathlib.Path):
    tmp_file = tmp_path / "openapi.json"
    openapi_json = tutorial003_py39.app.openapi()
    tmp_file.write_text(json.dumps(openapi_json))

    with patch("pathlib.Path", return_value=tmp_file):
        importlib.import_module("docs_src.generate_clients.tutorial004_py39")

from unittest.mock import patch

from docs_src.python_types.tutorial006_py39 import process_items


def test_process_items():
    with patch("builtins.print") as mock_print:
        process_items(["item_a", "item_b", "item_c"])

    assert mock_print.call_count == 3
    call_args = [arg.args for arg in mock_print.call_args_list]
    assert call_args == [
        ("item_a",),
        ("item_b",),
        ("item_c",),

{* ../../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] *}

from fastapi.testclient import TestClient

from docs_src.custom_response.tutorial006_py39 import app

client = TestClient(app)


def test_get():
    response = client.get("/typer", follow_redirects=False)
    assert response.status_code == 307, response.text
    assert response.headers["location"] == "https://typer.tiangolo.com"


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

{* ../../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] *}

from fastapi.testclient import TestClient

from docs_src.custom_response.tutorial006b_py39 import app

client = TestClient(app)


def test_redirect_response_class():
    response = client.get("/fastapi", follow_redirects=False)
    assert response.status_code == 307
    assert response.headers["location"] == "https://fastapi.tiangolo.com"


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: