/// tip

Pydantic có một hành vi đặc biệt khi bạn sử dụng `Optional` hoặc `Union[Something, None]` mà không có giá trị mặc dịnh, bạn có thể đọc nhiều hơn về nó trong tài liệu của Pydantic về <a href="https://docs.pydantic.dev/latest/concepts/models/#required-optional-fields" class="external-link" target="_blank">Required Optional fields</a>.

///

## Type Hints với Metadata Annotations

/// check | 😮 **FastAPI**

⚙️ 📟 🔬 "🔗" 👈 🚚 💽 🆎 & 🔬, 🔁.

///

### <a href="https://webargs.readthedocs.io/en/latest/" class="external-link" target="_blank">Webarg</a>

➕1️⃣ 🦏 ⚒ ✔ 🔗 <abbr title="reading and converting to Python data">✍</abbr> 📊 ⚪️➡️ 📨 📨.

Webarg 🧰 👈 ⚒ 🚚 👈 🔛 🔝 📚 🛠️, 🔌 🏺.

//// tab | Pydantic v2

У версії Pydantic 2 використовується атрибут `model_config`, який приймає `dict`, як описано в <a href="https://docs.pydantic.dev/latest/api/config/" class="external-link" target="_blank">документації Pydantic: Конфігурація</a>.

/// warning | Advertencia

Estos son detalles técnicos que podrías omitir si no es importante para ti en este momento.

///

`RequestValidationError` es una subclase de <a href="https://docs.pydantic.dev/latest/concepts/models/#error-handling" class="external-link" target="_blank">`ValidationError`</a> de Pydantic.

**FastAPI** la usa para que, si usas un modelo Pydantic en `response_model`, y tus datos tienen un error, lo verás en tu log.

Anwendungsserver, der den **WSGI-Standard** verwendet. Das bedeutet, dass Gunicorn Anwendungen wie Flask und Django ausliefern kann. Gunicorn selbst ist nicht mit **FastAPI** kompatibel, da FastAPI den neuesten **<a href="https://asgi.readthedocs.io/en/latest/" class="external-link" target="_blank">ASGI-Standard</a>** verwendet.

Aber Gunicorn kann als **Prozessmanager** arbeiten und Benutzer können ihm mitteilen, welche bestimmte **Workerprozessklasse** verwendet werden soll. Dann würde Gunicorn...

/// warning | Aviso

Você pode pular estes detalhes técnicos caso eles não sejam importantes para você neste momento.

///

`RequestValidationError` é uma subclasse do <a href="https://docs.pydantic.dev/latest/#error-handling" class="external-link" target="_blank">`ValidationError`</a> existente no Pydantic.

<img src="/img/tutorial/bigger-applications/image01.png">

## 🔌 🎏 📻 💗 🕰 ⏮️ 🎏 `prefix`

👆 💪 ⚙️ `.include_router()` 💗 🕰 ⏮️ *🎏* 📻 ⚙️ 🎏 🔡.

👉 💪 ⚠, 🖼, 🎦 🎏 🛠️ 🔽 🎏 🔡, ✅ `/api/v1` &amp; `/api/latest`.

👉 🏧 ⚙️ 👈 👆 5️⃣📆 🚫 🤙 💪, ✋️ ⚫️ 📤 💼 👆.

## 🔌 `APIRouter` ➕1️⃣

🎏 🌌 👆 💪 🔌 `APIRouter` `FastAPI` 🈸, 👆 💪 🔌 `APIRouter` ➕1️⃣ `APIRouter` ⚙️:

```Python

Вот несколько способов, как это можно сделать.

## Pydantic `schema_extra`

Вы можете объявить ключ `example` для модели Pydantic, используя класс `Config` и переменную `schema_extra`, как описано в <a href="https://docs.pydantic.dev/latest/concepts/json_schema/#schema-customization" class="external-link" target="_blank">Pydantic документации: Настройка схемы</a>:

{* ../../docs_src/schema_extra_example/tutorial001_py310.py hl[13:21] *}

/// tip

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

///

## 🆎 🔑 **FastAPI**

**FastAPI** ✊ 📈 👫 🆎 🔑 📚 👜.

⏮️ **FastAPI** 👆 📣 🔢 ⏮️ 🆎 🔑 &amp; 👆 🤚:

            ArtifactRepository localRepository)
            throws RepositoryMetadataStoreException {
        // TODO currently this is first wins, but really we should take the latest by comparing either the
        // snapshot timestamp, or some other timestamp later encoded into the metadata.
        // TODO this needs to be repeated here so the merging doesn't interfere with the written metadata