@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>Или используйте <code>async def</code>...</summary>

Если ваш код использует `async` / `await`, используйте `async def`:

```Python hl_lines="9  14"
from typing import Union

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


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

<details markdown="1">
<summary>Oppure usa <code>async def</code>...</summary>

Se il tuo codice usa `async` / `await`, allora usa `async def`:

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

INFO:     Application startup complete.
```

</div>

<details markdown="1">
<summary>关于 <code>uvicorn main:app --reload</code> 命令......</summary>

 `uvicorn main:app` 命令含义如下:

* `main`：`main.py` 文件（一个 Python "模块"）。
* `app`：在 `main.py` 文件中通过 `app = FastAPI()` 创建的对象。
* `--reload`：让服务器在更新代码后重新启动。仅在开发时使用该选项。

</details>

### 检查

I will show you some of the main concepts you should probably keep in mind when deploying a **FastAPI** application (although most of it applies to any other type of web application).

@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>Or use <code>async def</code>...</summary>

If your code uses `async` / `await`, use `async def`:

```Python hl_lines="9  14"
from typing import Union

from fastapi import 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>Oder verwenden Sie <code>async def</code> ...</summary>

Wenn Ihr Code `async` / `await` verwendet, benutzen Sie `async def`:

```Python hl_lines="9  14"
from typing import Union

@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>או השתמשו ב - <code>async def</code>...</summary>

אם הקוד שלכם משתמש ב - `async` / `await`, השתמשו ב - `async def`:

```Python hl_lines="9  14"
from typing import Union

@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>

اگر در کدتان از `async` / `await` استفاده می‌کنید، از `async def` برای تعریف تابع خود استفاده کنید:

Konzepte, die Sie beim Deployment einer **FastAPI**-Anwendung wahrscheinlich berücksichtigen sollten (obwohl das meiste davon auch für jede andere Art von Webanwendung gilt).

In den nächsten Abschnitten erfahren Sie mehr über die zu beachtenden Details und über die Techniken, das zu tun. ✨...

@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>Ou use <code>async def</code>...</summary>

Se seu código utiliza `async` / `await`, use `async def`:

```Python hl_lines="9  14"
from typing import Union