```JSON
{
  "title": "towel",
  "size": "XL"
}
```

You will receive a response telling you that the data is invalid containing the received body:

```JSON hl_lines="12-15"
{
  "detail": [
    {
      "loc": [
        "body",
        "size"
      ],
      "msg": "value is not a valid integer",
      "type": "type_error.integer"
    }
  ],

    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 = FastAPI()


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


@app.get("/items/{item_id}")

    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 typing import Union

from fastapi import FastAPI

app = FastAPI()


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


@app.get("/items/{item_id}")

<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:

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

from fastapi import FastAPI

app = FastAPI()


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

<font color="#4E9A06">INFO</font>:     Waiting for application startup.
<font color="#4E9A06">INFO</font>:     Application startup complete.
```

</div>

У консолі буде рядок приблизно такого змісту:

```hl_lines="4"
INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

Цей рядок показує URL, за яким додаток запускається на вашій локальній машині.

### Перевірте

Bạn cũng có thể tạo các biến môi trường **bên ngoài** đoạn mã Python, trong terminal (hoặc bằng bất kỳ phương pháp nào khác), và sau đó **đọc chúng trong Python**.

Ví dụ, bạn có một file `main.py` với:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

                        timestamp:
                          type: string
                          format: date-time
                          example: "2017-10-09T22:28:56.000Z"
                        url_link:
                          type: string
                          example: "https://fess.codelibs.org/"
                        created:
                          type: string
                          format: date-time

     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Application startup complete.
```

</div>

In the output, there's a line with something like:

```hl_lines="4"
INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

That line shows the URL where your app is being served, in your local machine.

### Check it { #check-it }

Hello Wade Wilson
```

</div>

////

## Pythonで環境変数を読み取る

環境変数をPythonの**外側**、ターミナル（や他の方法）で作成し、**Python内で読み取る**こともできます。

例えば、以下のような`main.py`ファイルを用意します:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

`uvicorn main:app`は以下を示します:

* `main`: `main.py`ファイル (Python "module")。
* `app`:  `main.py`内部で作られるobject（`app = FastAPI()`のように記述される）。
* `--reload`: コードの変更時にサーバーを再起動させる。開発用。

///

出力には次のような行があります:

```hl_lines="4"
INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

この行はローカルマシンでアプリが提供されているURLを示しています。

### チェック