dụng** đầu tiên (những gì bạn đang đọc).

Nó được thiết kế do đó bạn có thể xây dựng một ứng dụng hoàn chỉnh chỉ với **Hướng dẫn sử dụng**, và sau đó mở rộng nó theo các cách khác nhau, phụ thuộc vào những gì bạn cần, sử dụng một vài ý tưởng bổ sung từ **Hướng dẫn sử dụng nâng cao**....

### The callback path expression

The callback *path* can have an <a href="https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.1.0.md#key-expression" class="external-link" target="_blank">OpenAPI 3 expression</a> that can contain parts of the original request sent to *your API*.

In this case, it's the `str`:

```Python

Il est tout de même possible d'utiliser `BackgroundTask` seul dans **FastAPI**, mais dans ce cas il faut créer l'objet dans le code et renvoyer une `Response` Starlette l'incluant.

Plus de détails sont disponibles dans <a href="https://www.starlette.io/background/" class="external-link" target="_blank">la documentation officielle de Starlette sur les tâches d'arrière-plan</a> (via leurs classes `BackgroundTasks`et `BackgroundTask`).

@app.post("/send-notification/{email}")
async def send_notification(email: str, background_tasks: BackgroundTasks):
    background_tasks.add_task(write_notification, email, message="some notification")

!!! warning "Attention"
    Si vous n'êtes pas un "expert" en OpenAPI, vous n'en avez probablement pas besoin.

        os.remove(log)  # pragma: no cover
    response = client.post("/send-notification/******@****.***?q=some-query")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Message sent"}
    with open("./log.txt") as f:

        os.remove(log)  # pragma: no cover
    response = client.post("/send-notification/******@****.***?q=some-query")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Message sent"}
    with open("./log.txt") as f:

async def send_notification(
    email: str, background_tasks: BackgroundTasks, q: str = Depends(get_query)
):
    message = f"message to {email}\n"
    background_tasks.add_task(write_log, message)

from dirty_equals import IsDict
from fastapi.testclient import TestClient

from docs_src.schema_extra_example.tutorial004 import app

client = TestClient(app)


# Test required and embedded body parameters with no bodies sent
def test_post_body_example():
    response = client.put(
        "/items/5",
        json={
            "name": "Foo",
            "description": "A very nice Item",
            "price": 35.4,

@pytest.fixture(name="client")
def get_client():
    from docs_src.schema_extra_example.tutorial004_py310 import app

    client = TestClient(app)
    return client


# Test required and embedded body parameters with no bodies sent
@needs_py310
def test_post_body_example(client: TestClient):
    response = client.put(
        "/items/5",
        json={
            "name": "Foo",
            "description": "A very nice Item",