It is just a standard function that can receive parameters.

It can be an `async def` or normal `def` function, **FastAPI** will know how to handle it correctly.

In this case, the task function will write to a file (simulating sending an email).

And as the write operation doesn't use `async` and `await`, we define the function with normal `def`:

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

É apenas uma função padrão que pode receber parâmetros.

Pode ser uma função `async def` ou `def` normal, o **FastAPI** saberá como lidar com isso corretamente.

Nesse caso, a função de tarefa gravará em um arquivo (simulando o envio de um e-mail).

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

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

**FastAPI** stellt sicher, dass diese Daten korrekt ausgelesen werden, statt JSON zu erwarten.

/// note | Technische Details

Daten aus Formularen werden normalerweise mit dem <abbr title='Media type – Medientyp, Typ des Mediums'>„media type“</abbr> `application/x-www-form-urlencoded` kodiert.

app = FastAPI()


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


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

<details markdown="1">
<summary>Tàbí lò <code>async def</code>...</summary>

Tí kóòdù rẹ̀ bá ń lò `async` / `await`, lò `async def`:

```Python hl_lines="9  14"

from fastapi import FastAPI

app = FastAPI()


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


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

<details markdown="1">
<summary>همچنین می‌توانید از <code>async def</code>... نیز استفاده کنید</summary>

    }

    /**
     * Test decrypt with DES encryption.
     *
     * @throws GeneralSecurityException if a security error occurs
     * @throws NoSuchAlgorithmException if the algorithm is not available
     */
    @Test
    void testDecryptDes() throws GeneralSecurityException, NoSuchAlgorithmException {
        KeyGenerator keyGen = KeyGenerator.getInstance("DES");
        keyGen.init(56);

    assertThat(response1.body.source().readUtf8(3)).isEqualTo("ABC")
    assertThat(response2.body.source().readUtf8(3)).isEqualTo("GHI")
    assertThat(response1.body.source().readUtf8(3)).isEqualTo("DEF")
    assertThat(response2.body.source().readUtf8(3)).isEqualTo("JKL")
    val c0e0 = server.takeRequest()
    assertThat(c0e0.connectionIndex).isEqualTo(0)
    assertThat(c0e0.exchangeIndex).isEqualTo(0)

```
pip install fastapi
```

Installez également `uvicorn` pour qu'il fonctionne comme serveur :

```
pip install uvicorn
```

Et la même chose pour chacune des dépendances facultatives que vous voulez utiliser.

///

## Guide utilisateur avancé

Il existe également un **Guide d'utilisation avancé** que vous pouvez lire plus tard après ce **Tutoriel - Guide d'utilisation**.

      - name: Run source distribution tests
        run: |
          cd dist/fastapi*/
          bash scripts/test.sh
      - name: Build wheel distribution
        run: |
          cd dist
          pip wheel --no-deps fastapi*.tar.gz
      - name: Dump GitHub context
        env:
          GITHUB_CONTEXT: ${{ toJson(github) }}
        run: echo "$GITHUB_CONTEXT"

  # https://github.com/marketplace/actions/alls-green#why

Irgendwann sind die Funktions-Parameter fertig, Sie starten mit der Definition des Körpers ...

Aber dann müssen Sie „diese Methode aufrufen, die den ersten Buchstaben in Großbuchstaben umwandelt“.

War es `upper`? War es `uppercase`? `first_uppercase`? `capitalize`?

Dann versuchen Sie es mit dem langjährigen Freund des Programmierers, der Editor-Autovervollständigung.