```

=== "Python 3.10+ non-Annotated"

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="7"
    {!> ../../../docs_src/query_params_str_validations/tutorial003_py310.py!}
    ```

=== "Python 3.8+ non-Annotated"

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="10"

    ```

=== "🐍 3️⃣.1️⃣0️⃣ & 🔛"

    ```Python hl_lines="7"
    {!> ../../../docs_src/query_params_str_validations/tutorial006c_py310.py!}
    ```

!!! tip

    ```

=== "Python 3.10+ без Annotated"

    !!! tip "Подсказка"
        Рекомендуется использовать версию с `Annotated` если возможно.

    ```Python hl_lines="7"
    {!> ../../../docs_src/query_params_str_validations/tutorial003_py310.py!}
    ```

=== "Python 3.8+ без Annotated"

    !!! tip "Подсказка"
        Рекомендуется использовать версию с `Annotated` если возможно.

    ```

=== "Python 3.10+ nicht annotiert"

    !!! tip "Tipp"
        Bevorzugen Sie die `Annotated`-Version, falls möglich.

    ```Python hl_lines="7"
    {!> ../../../docs_src/query_params_str_validations/tutorial003_py310.py!}
    ```

=== "Python 3.8+ nicht annotiert"

    !!! tip "Tipp"
        Bevorzugen Sie die `Annotated`-Version, falls möglich.

你可以声明一个参数可以接收`None`值，但它仍然是必需的。这将强制客户端发送一个值，即使该值是`None`。

为此，你可以声明`None`是一个有效的类型，并仍然使用`default=...`：

```Python hl_lines="9"
{!../../../docs_src/query_params_str_validations/tutorial006c.py!}
```

!!! tip