```

## 定义 `Form` 参数

创建表单（`Form`）参数的方式与 `Body` 和 `Query` 一样：

```Python hl_lines="7"
{!../../docs_src/request_forms/tutorial001.py!}
```

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。

    def __call__(self, q: str = ""):
        if q:
            return self.fixed_content in q
        return False


checker = FixedContentQueryChecker("bar")


@app.get("/query-checker/")
async def read_query_check(fixed_content_included: Annotated[bool, Depends(checker)]):

        final String[] queries = getParamValueArray(request, "facet.query");
        if (fields.length == 0 && queries.length == 0) {
            return null;
        }
        final FacetInfo facetInfo = new FacetInfo();
        facetInfo.field = fields;
        facetInfo.query = queries;
        final String sizeStr = request.getParameter("facet.size");

            if (StringUtil.isBlank(fessConfig.getSchedulerTargetName())) {
                cb.query().setTarget_Equal(Constants.DEFAULT_JOB_TARGET);
            } else {
                cb.query().setTarget_InScope(Lists.newArrayList(Constants.DEFAULT_JOB_TARGET, fessConfig.getSchedulerTargetName()));
            }
            cb.query().addOrderBy_CreatedTime_Asc();

		},
	}

	u, err := url.Parse("http://127.0.0.1:8443/?Token=invalid")
	if err != nil {
		t.Fatal(err)
	}

	var claims jwtgo.MapClaims
	if err = cfg.Validate(context.Background(), DummyRoleARN, u.Query().Get("Token"), "", "", claims); err == nil {
		t.Fatal(err)
	}
}

func TestDefaultExpiryDuration(t *testing.T) {
	testCases := []struct {
		reqURL    string
		duration  time.Duration
		expectErr bool

И она может возвращать всё, что требуется.

В этом случае, эта зависимость ожидает:

* Необязательный query-параметр `q` с типом `str`
* Необязательный query-параметр `skip` с типом `int`, и значением по умолчанию `0`
* Необязательный query-параметр `limit` с типом `int`, и значением по умолчанию `100`

И в конце она возвращает `dict`, содержащий эти значения.

/// info | "Информация"

```Python hl_lines="4  10-13"
{!> ../../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**.

from pydantic.fields import FieldInfo
from typing_extensions import Annotated, deprecated

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,
        *,

def write_log(message: str):
    with open("log.txt", mode="a") as log:
        log.write(message)


def get_query(background_tasks: BackgroundTasks, q: Union[str, None] = None):
    if q:
        message = f"found query: {q}\n"
        background_tasks.add_task(write_log, message)
    return q


@app.post("/send-notification/{email}")
async def send_notification(

        </ul>
    </div>
    <div id="content"></div>
    <div id="form">
        <form method="post" action="form.html">
            <input type="text" name="query" value="aaa">
            <input type="hidden" name="secret" value="xxx">
            <input type="submit" name="Submit">
        </form>
    </div>
	<a href="#" onclick="addFooter('XXX')">Footer</a>
	<div id="footer">