```

/// warning | "警告"

当你直接返回一个像上面例子中的 `Response` 对象时，它会直接返回。

FastAPI 不会用模型等对该响应进行序列化。

确保其中有你想要的数据，且返回的值为合法的 JSON（如果你使用 `JSONResponse` 的话）。

///

/// note | "技术细节"

你也可以使用 `from starlette.responses import JSONResponse`。　

出于方便，**FastAPI** 为开发者提供同 `starlette.responses` 一样的 `fastapi.responses`。但是大多数可用的响应都是直接来自 Starlette。`status` 也是一样。

///

## OpenAPI 和 API 文档

///

/// 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"

与 JSON 不同，HTML 表单（`<form></form>`）向服务器发送数据通常使用「特殊」的编码。

**FastAPI** 要确保从正确的位置读取数据，而不是读取 JSON。

/// note | "技术细节"

表单数据的「媒体类型」编码一般为 `application/x-www-form-urlencoded`。

但包含文件的表单编码为 `multipart/form-data`。文件处理详见下节。

    app = FastAPI()

    class ModelB(BaseModel):
        username: str

    class ModelC(ModelB):
        password: str

    class ModelA(BaseModel):
        name: str
        description: Optional[str] = None
        foo: ModelB

        @field_validator("name")
        def lower_username(cls, name: str, info: ValidationInfo):
            if not name.endswith("A"):
                raise ValueError("name must end in A")

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

 * NullPointerTester}, {@link EqualsTester} and {@link SerializableTester}. For example:
 *
 * <pre>
 * public class PackageSanityTests extends AbstractPackageSanityTests {}
 * </pre>
 *
 * <p>Note that only top-level classes with either a non-private constructor or a non-private static
 * factory method to construct instances can have their instance methods checked. For example:
 *
 * <pre>
 * public class Address {

そしてもし、`Response` が、`JSONResponse` や `UJSONResponse` の場合のようにJSONメディアタイプ (`application/json`) ならば、データは *path operationデコレータ* に宣言したPydantic `response_model` により自動的に変換 (もしくはフィルタ) されます。

/// note | "備考"

メディアタイプを指定せずにレスポンスクラスを利用すると、FastAPIは何もコンテンツがないことを期待します。そのため、生成されるOpenAPIドキュメントにレスポンスフォーマットが記載されません。

///

## `ORJSONResponse` を使う

  //   list of labels in the path split by the '/' separator. A request is a
  //   match for path p if every p is an element-wise prefix of p of the
  //   request path. Note that if the last element of the path is a substring
  //   of the last element in request path, it is not a match (e.g. /foo/bar
  //   matches /foo/bar/baz, but does not match /foo/barbaz).

但该异常将会被 `unicorn_exception_handler` 处理。

接收到的错误信息清晰明了，HTTP 状态码为 `418`，JSON 内容如下：

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}

```

/// note | "技术细节"

`from starlette.requests import Request` 和 `from starlette.responses import JSONResponse` 也可以用于导入 `Request` 和 `JSONResponse`。

**Raspberry Pi 2 and 3**      | [![Status](https://storage.googleapis.com/tensorflow-kokoro-build-badges/rpi23-py3.svg)](https://storage.googleapis.com/tensorflow-kokoro-build-badges/rpi23-py3.html)           | [Py3](https://storage.googleapis.com/tensorflow-nightly/tensorflow-1.10.0-cp34-none-linux_armv7l.whl)