# 使用数据类

FastAPI 基于 **Pydantic** 构建，前文已经介绍过如何使用 Pydantic 模型声明请求与响应。

但 FastAPI 还可以使用数据类（<a href="https://docs.python.org/3/library/dataclasses.html" class="external-link" target="_blank">`dataclasses`</a>）：

{* ../../docs_src/dataclasses_/tutorial001.py hl[1,7:12,19:20] *}

这还是借助于 **Pydantic** 及其<a href="https://pydantic-docs.helpmanual.io/usage/dataclasses/#use-of-stdlib-dataclasses-with-basemodel" class="external-link" target="_blank">内置的 `dataclasses`</a>。

**FastAPI** **извлечёт** данные для **каждого поля** из **данных формы** в запросе и выдаст вам объявленную Pydantic-модель.

## Проверьте документацию { #check-the-docs }

Вы можете проверить это в интерфейсе документации по адресу `/docs`:

<div class="screenshot">
<img src="/img/tutorial/request-form-models/image01.png">
</div>

## Запрет дополнительных полей формы { #forbid-extra-form-fields }

**FastAPI** **extraerá** los datos para **cada campo** de los **parámetros query** en el request y te proporcionará el modelo de Pydantic que definiste.

## Revisa la Documentación { #check-the-docs }

Puedes ver los parámetros query en la UI de documentación en `/docs`:

<div class="screenshot">
<img src="/img/tutorial/query-param-models/image01.png">
</div>

## Prohibir Parámetros Query Extras { #forbid-extra-query-parameters }

                It will be included in the generated OpenAPI (e.g. visible at `/docs`).
                """
            ),
        ] = None,
        description: Annotated[
            Optional[str],
            Doc(
                """
                Security scheme description.

                It will be included in the generated OpenAPI (e.g. visible at `/docs`).
                """
            ),
        ] = None,

                owner_html_url=repo.owner.html_url,
            )
        )
    data = [repo.model_dump() for repo in final_repos]

    # Local development
    # repos_path = Path("../docs/en/data/topic_repos.yml")
    repos_path = Path("./docs/en/data/topic_repos.yml")
    repos_old_content = repos_path.read_text(encoding="utf-8")
    new_repos_content = yaml.dump(data, sort_keys=False, width=200, allow_unicode=True)

    assert response.status_code == 200, response.text
    assert response.json() == {"id": "foo", "value": "there goes my hero"}


def test_path_operation_img(client: TestClient):
    shutil.copy("./docs/en/docs/img/favicon.png", "./image.png")
    response = client.get("/items/foo?img=1")
    assert response.status_code == 200, response.text
    assert response.headers["Content-Type"] == "image/png"
    assert len(response.content)

-e .[all]
-r requirements-tests.txt
-r requirements-docs.txt
-r requirements-translations.txt
prek==0.2.22
# For generating screenshots

```JSON
{"item_id": 5, "q": "somequery"}
```

## Interactive API docs { #interactive-api-docs }

Now you can go to <a href="http://192.168.99.100/docs" class="external-link" target="_blank">http://192.168.99.100/docs</a> or <a href="http://127.0.0.1/docs" class="external-link" target="_blank">http://127.0.0.1/docs</a> (or equivalent, using your Docker host).

## Dokumentations-URLs { #docs-urls }

Sie können die beiden enthaltenen Dokumentationsbenutzeroberflächen konfigurieren:

* **Swagger UI**: bereitgestellt unter `/docs`.
    * Sie können deren URL mit dem Parameter `docs_url` festlegen.
    * Sie können sie deaktivieren, indem Sie `docs_url=None` festlegen.

Aber FastAPI unterstützt auf die gleiche Weise auch die Verwendung von <a href="https://docs.python.org/3/library/dataclasses.html" class="external-link" target="_blank">`dataclasses`</a>:

{* ../../docs_src/dataclasses_/tutorial001_py310.py hl[1,6:11,18:19] *}