<img src="/img/python-types/image06.png">

Lưu ý rằng, điều này có nghĩa rằng "`one_person`" là một **thực thể** của lớp `Person`.

Nó không có nghĩa "`one_person`" là một **lớp** gọi là `Person`.

## Pydantic models

<a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a> là một thư viện Python để validate dữ liệu hiệu năng cao.

    * les types Python (`str`, `int`, `float`, `bool`, `list`, etc).
    * les objets `datetime`.
    * les objets `UUID`.
    * les modèles de base de données.
    * ... et beaucoup plus.
* La documentation API interactive automatique, avec 2 interfaces utilisateur au choix :
    * Swagger UI.
    * ReDoc.

---

### `RequestValidationError` vs `ValidationError`

/// warning | "警告"

如果您觉得现在还用不到以下技术细节，可以先跳过下面的内容。

///

`RequestValidationError` 是 Pydantic 的 <a href="https://docs.pydantic.dev/latest/concepts/models/#error-handling" class="external-link" target="_blank">`ValidationError`</a> 的子类。

**FastAPI** 调用的就是 `RequestValidationError` 类，因此，如果在 `response_model` 中使用 Pydantic 模型，且数据有错误时，在日志中就会看到这个错误。

import org.apache.maven.api.model.Repository;
import org.apache.maven.api.model.Resource;
import org.apache.maven.model.Model;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblem.Severity;
import org.apache.maven.model.building.ModelProblem.Version;
import org.apache.maven.model.building.ModelProblemCollector;
import org.apache.maven.model.building.ModelProblemCollectorRequest;

{*../../docs_src/python_types/tutorial010.py hl[6] *}

Et vous aurez accès, encore une fois, au support complet offert par l'éditeur :

<img src="/img/python-types/image06.png">

## Les modèles Pydantic

<a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a> est une bibliothèque Python pour effectuer de la validation de données.

    full_name = user_dict["full_name"],
    disabled = user_dict["disabled"],
    hashed_password = user_dict["hashed_password"],
)
```

/// info | "说明"

`user_dict` 的说明，详见[**更多模型**一章](../extra-models.md#user_indict){.internal-link target=_blank}。

///

## 返回 Token

`token` 端点的响应必须是 JSON 对象。

响应返回的内容应该包含 `token_type`。本例中用的是**Bearer**Token，因此， Token 类型应为**`bearer`**。

Non c'è bisogno di imparare una nuova sintassi, metodi o classi specifici a una libreria, ecc.

È normalissimo **Python 3.6+**.

Per esempio, per un `int`:

```Python
item_id: int
```

o per un modello `Item` più complesso:

```Python
item: Item
```

...e con quella singola dichiarazione hai in cambio:

* Supporto per gli editor di testo, incluso:
    * Autocompletamento.

    * Convert Python types (`str`, `int`, `float`, `bool`, `list`, etc).
    * `datetime` objects.
    * `UUID` objects.
    * Database models.
    * ...and many more.
* Automatic interactive API documentation, including 2 alternative user interfaces:
    * Swagger UI.
    * ReDoc.

---

Coming back to the previous code example, **FastAPI** will:

inside and make sure it is serializable as JSON, using the same [JSON Compatible Encoder](../tutorial/encoder.md){.internal-link target=_blank} explained in the tutorial. This is what allows you to return **arbitrary objects**, for example database models.

But if you are certain that the content that you are returning is **serializable with JSON**, you can pass it directly to the response class and avoid the extra overhead that FastAPI would have by passing your return content through the...

```

////

/// tip

Pydantic, ❔ ⚫️❔ 🏋️ 🌐 💽 🔬 &amp; 🛠️ FastAPI, ✔️ 🎁 🎭 🕐❔ 👆 ⚙️ `Optional` ⚖️ `Union[Something, None]` 🍵 🔢 💲, 👆 💪 ✍ 🌅 🔃 ⚫️ Pydantic 🩺 🔃 <a href="https://docs.pydantic.dev/latest/concepts/models/#required-optional-fields" class="external-link" target="_blank">✔ 📦 🏑</a>.

///

### ⚙️ Pydantic `Required` ↩️ ❕ (`...`)

🚥 👆 💭 😬 ⚙️ `...`, 👆 💪 🗄 &amp; ⚙️ `Required` ⚪️➡️ Pydantic: