{!> ../../../docs_src/schema_extra_example/tutorial002.py!}
    ```

## `examples` in JSON Schema - OpenAPI

When using any of:

* `Path()`
* `Query()`
* `Header()`
* `Cookie()`
* `Body()`
* `Form()`
* `File()`

you can also declare a group of `examples` with additional information that will be added to their **JSON Schemas** inside of **OpenAPI**.

### `Body` with `examples`

from ._compat import PYDANTIC_V2, PYDANTIC_VERSION, Undefined

_Unset: Any = Undefined


class ParamTypes(Enum):
    query = "query"
    header = "header"
    path = "path"
    cookie = "cookie"


class Param(FieldInfo):
    in_: ParamTypes

    def __init__(
        self,
        default: Any = Undefined,
        *,
        default_factory: Union[Callable[[], Any], None] = _Unset,

```

例如，OAuth2 规范的 "密码流" 模式规定要通过表单字段发送 `username` 和 `password`。

<abbr title="specification">该规范</abbr>要求字段必须命名为 `username` 和 `password`，并通过表单字段发送，不能用 JSON。

使用 `Form` 可以声明与 `Body` （及 `Query`、`Path`、`Cookie`）相同的元数据和验证。

!!! info "说明"

    `Form` 是直接继承自 `Body` 的类。

!!! tip "提示"

    声明表单体要显式使用 `Form` ，否则，FastAPI 会把该参数当作查询参数或请求体（JSON）参数。

## 关于 "表单字段"

Com `Form` você pode declarar os mesmos metadados e validação que com `Body` (e `Query`, `Path`, `Cookie`).

!!! info "Informação"
    `Form` é uma classe que herda diretamente de `Body`.

!!! tip "Dica"

With `Form` you can declare the same configurations as with `Body` (and `Query`, `Path`, `Cookie`), including validation, examples, an alias (e.g. `user-name` instead of `username`), etc.

!!! info
    `Form` is a class that inherits directly from `Body`.

!!! tip

Вы можете настроить `Form` точно так же, как настраиваете и  `Body` ( `Query`, `Path`, `Cookie`), включая валидации, примеры, псевдонимы (например, `user-name` вместо `username`) и т.д.

!!! info "Дополнительная информация"
    `Form` - это класс, который наследуется непосредственно от `Body`.

!!! tip "Подсказка"

                It is also useful when you want to have authentication that can be
                provided in one of multiple optional ways (for example, in an HTTP
                Bearer token or in a cookie).
                """
            ),
        ] = True,
    ):
        self.model = HTTPBearerModel(bearerFormat=bearerFormat, description=description)

`Form` sınıfıyla tanımlama yaparken `Body`, `Query`, `Path` ve `Cookie` sınıflarında kullandığınız aynı validasyon, örnekler, isimlendirme (örneğin `username` yerine `user-name` kullanımı) ve daha fazla konfigurasyonu kullanabilirsiniz.

!!! info "Bilgi"

#                                                     Cookie
#                                                     ------
# The default path of cookie (basically '/' if no context path)
cookie.default.path = /

# The default expire of cookie in seconds e.g. 31556926: one year, 86400: one day
cookie.default.expire = 3600

session.tracking.modes=cookie

# ----------------------------------------------------------

Mit `Form` haben Sie die gleichen Konfigurationsmöglichkeiten wie mit `Body` (und `Query`, `Path`, `Cookie`), inklusive Validierung, Beispielen, einem Alias (z. B. `user-name` statt `username`), usw.

!!! info
    `Form` ist eine Klasse, die direkt von `Body` erbt.

!!! tip "Tipp"