=== "Python 3.10+"

    ```Python hl_lines="4"
    {!> ../../../docs_src/body_fields/tutorial001_an_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="4"
    {!> ../../../docs_src/body_fields/tutorial001_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="4"
    {!> ../../../docs_src/body_fields/tutorial001_an.py!}
    ```

=== "Python 3.10+ non-Annotated"

    !!! tip

# Body - Nested Models

With **FastAPI**, you can define, validate, document, and use arbitrarily deeply nested models (thanks to Pydantic).

## List fields

You can define an attribute to be a subtype. For example, a Python `list`:

=== "Python 3.10+"

    ```Python hl_lines="12"
    {!> ../../../docs_src/body_nested_models/tutorial001_py310.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="14"

    If you want to read more about these encodings and form fields, head to the <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST" class="external-link" target="_blank"><abbr title="Mozilla Developer Network">MDN</abbr> web docs for <code>POST</code></a>.

!!! warning

    ```Python hl_lines="20-27"
    {!> ../../../docs_src/schema_extra_example/tutorial003.py!}
    ```

### 문서 UI 예시

위의 어느 방법과 함께라면 `/docs`에서 다음과 같이 보일 것입니다:

<img src="/img/tutorial/body-fields/image01.png">

### 다중 `examples`를 포함한 `Body`

물론 여러 `examples`를 넘길 수 있습니다:

=== "Python 3.10+"

    ```Python hl_lines="23-38"
    {!> ../../../docs_src/schema_extra_example/tutorial004_an_py310.py!}

## Multiple models

Here's a general idea of how the models could look like with their password fields and the places where they are used:

=== "Python 3.10+"

    ```Python hl_lines="7  9  14  20  22  27-28  31-33  38-39"
    {!> ../../../docs_src/extra_models/tutorial001_py310.py!}
    ```

=== "Python 3.8+"

    - tutorial/query-params.md
    - tutorial/body.md
    - tutorial/query-params-str-validations.md
    - tutorial/path-params-numeric-validations.md
    - tutorial/body-multiple-params.md
    - tutorial/body-fields.md
    - tutorial/body-nested-models.md
    - tutorial/schema-extra-example.md
    - tutorial/extra-data-types.md
    - tutorial/cookie-params.md
    - tutorial/header-params.md
    - tutorial/response-model.md

### Validation

* Validation for most (or all?) Python **data types**, including:
    * JSON objects (`dict`).
    * JSON array (`list`) defining item types.
    * String (`str`) fields, defining min and max lengths.
    * Numbers (`int`, `float`) with min and max values, etc.

* Validation for more exotic types, like:
    * URL.
    * Email.
    * UUID.
    * ...and others.

!!! tip
    Remember that in most of the cases, when something is required, you can simply omit the default, so you normally don't have to use `...`.

=== "Python 3.10+"

    ```Python hl_lines="4"
    {!> ../../../docs_src/body_fields/tutorial001_an_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="4"
    {!> ../../../docs_src/body_fields/tutorial001_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="4"
    {!> ../../../docs_src/body_fields/tutorial001_an.py!}
    ```

=== "Python 3.10+ nicht annotiert"

    !!! tip "Tipp"

!!! 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; 👆 🤚:

* **👨‍🎨 🐕‍🦺**.
* **🆎 ✅**.