Pero una variable como `user-agent` es inválida en Python.

Así que, por defecto, `Header` convertirá los caracteres de los nombres de los parámetros de guion bajo (`_`) a guion (`-`) para extraer y documentar los headers.

Además, los headers HTTP no diferencian entre mayúsculas y minúsculas, por lo que los puedes declarar con el estilo estándar de Python (también conocido como "snake_case").

```Python hl_lines="1"
async def get_burgers(number: int):
    # Mach Sie hier etwas Asynchrones, um die Burger zu erstellen
    return burgers
```

... statt mit `def`:

```Python hl_lines="2"
# Die ist nicht asynchron
def get_sequential_burgers(number: int):
    # Mach Sie hier etwas Sequentielles, um die Burger zu erstellen
    return burgers
```

Como, por defecto, los valores singulares se interpretan como parámetros de query, no tienes que añadir explícitamente un `Query`, solo puedes hacer:

```Python
q: Union[str, None] = None
```

O en Python 3.10 y superior:

```Python
q: str | None = None
```

Por ejemplo:

{* ../../docs_src/body_multiple_params/tutorial004_an_py310.py hl[28] *}

/// info | Información

* Full **Docker** entegrasyonu (Docker based).
* Docker Swarm Mode ile deployment.
* **Docker Compose** entegrasyonu ve lokal geliştirme için optimizasyon.
* Uvicorn ve Gunicorn ile **Production ready** Python web server'ı.
* Python <a href="https://github.com/fastapi/fastapi" class="external-link" target="_blank">**FastAPI**</a> backend:
    * **Hızlı**: **NodeJS** ve **Go** ile eşit, çok yüksek performans (Starlette ve Pydantic'e teşekkürler).

Da einfache Werte standardmäßig als Query-Parameter interpretiert werden, müssen Sie `Query` nicht explizit hinzufügen, Sie können einfach schreiben:

```Python
q: Union[str, None] = None
```

Oder in Python 3.10 und darüber:

```Python
q: str | None = None
```

Zum Beispiel:

{* ../../docs_src/body_multiple_params/tutorial004_an_py310.py hl[27] *}

/// info

As, by default, singular values are interpreted as query parameters, you don't have to explicitly add a `Query`, you can just do:

```Python
q: Union[str, None] = None
```

Or in Python 3.10 and above:

```Python
q: str | None = None
```

For example:

{* ../../docs_src/body_multiple_params/tutorial004_an_py310.py hl[28] *}


/// info

---

רק גרדנו את קצה הקרחון, אבל כבר יש לכם רעיון של איך הכל עובד.

נסו לשנות את השורה:

```Python
    return {"item_name": item.name, "item_id": item_id}
```

...מ:

```Python
        ... "item_name": item.name ...
```

...ל:

```Python
        ... "item_price": item.price ...
```

...וראו איך העורך שלכם משלים את המאפיינים ויודע את הטיפוסים שלהם:

# Status Codes

You can import the `status` module from `fastapi`:

```python
from fastapi import status
```

`status` is provided directly by Starlette.

It contains a group of named constants (variables) with integer status codes.

For example:

* 200: `status.HTTP_200_OK`
* 403: `status.HTTP_403_FORBIDDEN`
* etc.

# 파일 요청

`File`을 사용하여 클라이언트가 업로드할 파일들을 정의할 수 있습니다.

/// info | 정보

업로드된 파일을 전달받기 위해 먼저 <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>를 설치해야합니다.

예시) `pip install python-multipart`.

업로드된 파일들은 "폼 데이터"의 형태로 전송되기 때문에 이 작업이 필요합니다.

///

## `File` 임포트

`fastapi` 에서 `File` 과 `UploadFile` 을 임포트 합니다:

{* ../../docs_src/request_files/tutorial001.py hl[1] *}

## Types and validation { #types-and-validation }

These environment variables can only handle text strings, as they are external to Python and have to be compatible with other programs and the rest of the system (and even with different operating systems, as Linux, Windows, macOS).

That means that any value read in Python from an environment variable will be a `str`, and any conversion to a different type or any validation has to be done in code.