/// warning

The Pydantic team stopped support for Pydantic v1 for the latest versions of Python, starting with **Python 3.14**.

This includes `pydantic.v1`, which is no longer supported in Python 3.14 and above.

If you want to use the latest features of Python, you will need to make sure you use Pydantic v2.

///

{* ../../docs_src/app_testing/tutorial001_py310.py hl[2,12,15:18] *}

/// tip | 팁

테스트를 위한 함수는 `async def`가 아니라 `def`로 작성됨에 주의하세요.

그리고 클라이언트에 대한 호출도 `await`를 사용하지 않는 일반 호출입니다.

이렇게 하여 복잡한 과정 없이 `pytest`를 직접적으로 사용할 수 있습니다.

///

/// note | 기술 세부사항

`from starlette.testclient import TestClient` 역시 사용할 수 있습니다.

/// tip | Astuce

Si vous avez utilisé [`uv`](https://github.com/astral-sh/uv) pour créer l’environnement virtuel, il l’a déjà fait pour vous, vous pouvez passer cette étape. 😎

///

/// tip | Astuce

Faites cela une seule fois, juste après avoir créé l’environnement virtuel.

///

<div class="termy">

```console

@app.get("/items/{item_id}")
def read_item(item_id: int, q: str | None = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>或者使用 <code>async def</code>...</summary>

如果你的代码里会用到 `async` / `await`，请使用 `async def`：

```Python hl_lines="7  12"
from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():
    return {"Hello": "World"}

**FastAPI** est entièrement compatible avec (et basé sur) [**Starlette**](https://www.starlette.dev/). Donc, tout code Starlette additionnel que vous avez fonctionnera aussi.

`FastAPI` est en fait une sous-classe de `Starlette`. Ainsi, si vous connaissez ou utilisez déjà Starlette, la plupart des fonctionnalités fonctionneront de la même manière.

 * Converter.apply (like Converter.convert) is capable of accepting null inputs. However, a
 * supertype of `Function<A, B>` turns out to be massively more useful to callers in practice: They
 * want their output to be non-null in operations like `stream.map(myConverter)`, and we can
 * guarantee that as long as we also require the input type to be non-null[*] (which is a
 * requirement that existing callers already fulfill).

                (Strength) combination.get(6),
                (Strength) combination.get(7)));
  }

  /**
   * Sets.cartesianProduct doesn't allow sets that contain null, but we want null to mean "don't
   * call the associated CacheBuilder method" - that is, get the default CacheBuilder behavior. This
   * method wraps the elements in the input sets (which may contain null) as Optionals, calls

## Multiples paramètres de chemin et de requête { #multiple-path-and-query-parameters }

Vous pouvez déclarer plusieurs paramètres de chemin et paramètres de requête en même temps, **FastAPI** sait lequel est lequel.

Et vous n'avez pas besoin de les déclarer dans un ordre spécifique.

Ils seront détectés par leur nom :

{* ../../docs_src/query_params/tutorial004_py310.py hl[6,8] *}

Neste caso, a função da tarefa escreverá em um arquivo (simulando o envio de um e-mail).

E como a operação de escrita não usa `async` e `await`, definimos a função com um `def` normal:

{* ../../docs_src/background_tasks/tutorial001_py310.py hl[6:9] *}

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

        CountDownLatch latch = new CountDownLatch(shards.size());
        for (int i = 0; i < shards.size(); i++) {
            consumer.consumeResult(shards.get(i), () -> latch.countDown());
        }
        latch.await();
        SearchPhaseController.ReducedQueryPhase phase = consumer.reduce();
        executor.shutdownNow();
        return phase;
    }