class User(BaseModel):
    id: int
    name: str = "John Doe"
    signup_ts: Union[datetime, None] = None
    friends: List[int] = []


external_data = {
    "id": "123",
    "signup_ts": "2017-06-01 12:22",
    "friends": [1, "2", b"3"],
}
user = User(**external_data)
print(user)
# > User id=123 name='John Doe' signup_ts=datetime.datetime(2017, 6, 1, 12, 22) friends=[1, 2, 3]
print(user.id)

📂 👆 🖥 <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>.

👆 🔜 👀 🎻 📨:

```JSON
{"message": "Hello World"}
```

### 🎓 🛠️ 🩺

🔜 🚶 <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

👆 🔜 👀 🏧 🎓 🛠️ 🧾 (🚚 <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">🦁 🎚</a>):

## Testing locally with Traefik

You can easily run the experiment locally with a stripped path prefix using <a href="https://docs.traefik.io/" class="external-link" target="_blank">Traefik</a>.

<a href="https://github.com/containous/traefik/releases" class="external-link" target="_blank">Download Traefik</a>, it's a single binary, you can extract the compressed file and run it directly from the terminal.

```Python hl_lines="1  7-12  19-20"
{!../../../docs_src/dataclasses/tutorial001.py!}
```

This is still supported thanks to **Pydantic**, as it has <a href="https://docs.pydantic.dev/latest/concepts/dataclasses/#use-of-stdlib-dataclasses-with-basemodel" class="external-link" target="_blank">internal support for `dataclasses`</a>.

이전 스크린샷은 <a href="https://code.visualstudio.com" class="external-link" target="_blank">Visual Studio Code</a>를 찍은 것입니다.

하지만 똑같은 편집기 지원을 <a href="https://www.jetbrains.com/pycharm/" class="external-link" target="_blank">PyCharm</a>에서 받을 수 있거나, 대부분의 다른 편집기에서도 받을 수 있습니다:

<img src="/img/tutorial/body/image05.png">

!!! tip "팁"

### Check it

Open your browser at <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>.

You will see the JSON response as:

```JSON
{"message": "Hello World"}
```

### Interactive API docs

Now go to <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

📥 📶 ℹ ⏮️ ✍.

#### 💁‍♂ & 📄

* ✅ ⏳ <a href="https://github.com/tiangolo/fastapi/pulls" class="external-link" target="_blank">♻ 🚲 📨</a> 👆 🇪🇸 &amp; 🚮 📄 ✔ 🔀 ⚖️ ✔ 👫.

!!! tip
    👆 💪 <a href="https://help.github.com/en/github/collaborating-with-issues-and-pull-requests/commenting-on-a-pull-request" class="external-link" target="_blank">🚮 🏤 ⏮️ 🔀 🔑</a> ♻ 🚲 📨.

![Swagger UI](https://fastapi.tiangolo.com/img/index/index-01-swagger-ui-simple.png)

### 他のAPIドキュメント

次に、<a href="http://127.0.0.1:8000/redoc" class="external-link" target="_blank">http://127.0.0.1:8000/redoc</a>にアクセスします。

先ほどとは異なる、自動生成された対話的APIドキュメントが表示されます (<a href="https://github.com/Rebilly/ReDoc" class="external-link" target="_blank">ReDoc</a>によって提供):

* 👆 💪 🤚 🗃 ⚪️➡️ 📂 📁.
* ⚫️ ✔️ <a href="https://docs.python.org/3/glossary.html#term-file-like-object" class="external-link" target="_blank">📁-💖</a> `async` 🔢.
* ⚫️ 🎦 ☑ 🐍 <a href="https://docs.python.org/3/library/tempfile.html#tempfile.SpooledTemporaryFile" class="external-link" target="_blank">`SpooledTemporaryFile`</a> 🎚 👈 👆 💪 🚶‍♀️ 🔗 🎏 🗃 👈 ⌛ 📁-💖 🎚.

### `UploadFile`

`UploadFile` ✔️ 📄 🔢:

🚥 👆 🚫 😰 ⏮️ `f"userprofile::{username}"`, ⚫️ 🐍 "<a href="https://docs.python.org/3/glossary.html#term-f-string" class="external-link" target="_blank">Ⓜ-🎻</a>".

🙆 🔢 👈 🚮 🔘 `{}` Ⓜ-🎻 🔜 ↔ / 💉 🎻.

### `dict` 🏗

🚥 👆 🚫 😰 ⏮️ `UserInDB(**result.value)`, <a href="https://docs.python.org/3/glossary.html#term-argument" class="external-link" target="_blank">⚫️ ⚙️ `dict` "🏗"</a>.