"""
            ),
        ],
        reason: Annotated[
            Union[str, None],
            Doc(
                """
                The reason to close the WebSocket connection.

                It is UTF-8-encoded data. The interpretation of the reason is up to the
                application, it is not specified by the WebSocket specification.

So, you can use `user_agent` as you normally would in Python code, instead of needing to capitalize the first letters as `User_Agent` or something similar.

If for some reason you need to disable automatic conversion of underscores to hyphens, set the parameter `convert_underscores` of `Header` to `False`:

=== "Python 3.10+"

    ```Python hl_lines="10"

### Das Problem reproduzieren

In den meisten Fällen und bei den meisten Fragen ist etwas mit dem von der Person erstellten **eigenen Quellcode** los.

In vielen Fällen wird nur ein Fragment des Codes gepostet, aber das reicht nicht aus, um **das Problem zu reproduzieren**.

And you don't need to declare anything else for that parameter, so you don't really need to use `Query`.

But you still need to use `Path` for the `item_id` path parameter. And you don't want to use `Annotated` for some reason.

Python will complain if you put a value with a "default" before a value that doesn't have a "default".

But you can re-order them, and have the value without a default (the query parameter `q`) first.

<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.

    * 这个 `dict` 的所有值为 `float` 类型（可以看作是字典内每个元素的价格）。

### 类作为类型

你也可以将类声明为变量的类型。

假设你有一个名为 `Person` 的类，拥有 name 属性：

```Python hl_lines="1-3"
{!../../../docs_src/python_types/tutorial010.py!}
```

接下来，你可以将一个变量声明为 `Person` 类型：

```Python hl_lines="6"
{!../../../docs_src/python_types/tutorial010.py!}
```

然后，你将再次获得所有的编辑器支持：

    They are more relevant for older versions, before OpenAPI 3.1.0 was available.

    You can consider this a brief OpenAPI and JSON Schema **history lesson**. 🤓

!!! warning
    These are very technical details about the standards **JSON Schema** and **OpenAPI**.