* form model
* model object

* class
* base class
* parent class
* subclass
* child class
* sibling class
* class method

* header
* headers
* authorization header
* `Authorization` header
* forwarded header

* dependency injection system
* dependency
* dependable
* dependant

* I/O bound
* CPU bound
* concurrency
* parallelism
* multiprocessing

## Einen `Response`-Parameter verwenden { #use-a-response-parameter }

Sie können einen Parameter vom Typ `Response` in Ihrer *Pfadoperation-Funktion* deklarieren (wie Sie es auch für Cookies und Header tun können).

Anschließend können Sie den `status_code` in diesem *vorübergehenden* <abbr title="Response – Antwort: Daten, die der Server zum anfragenden Client zurücksendet">Response</abbr>-Objekt festlegen.

	r, e := http.NewRequest(http.MethodPost, reqURL, &body)
	if e != nil {
		return "", e
	}
	r.Header.Add("Content-Type", writer.FormDataContentType())

	return c.submitPost(r)
}

func (c Config) submitPost(r *http.Request) (string, error) {
	configLock.RLock()
	r.Header.Set(xhttp.SubnetAPIKey, c.APIKey)
	configLock.RUnlock()
	r.Header.Set(xhttp.MinioDeploymentID, xhttp.GlobalDeploymentID)

	client := &http.Client{

注意默认值依然是 `None`，所以该参数仍是可选的。

但现在把 `Query(max_length=50)` 放到 `Annotated` 里，我们就在告诉 FastAPI，这个值需要**额外校验**，最大长度为 50 个字符。😎

/// tip | 提示

这里用的是 `Query()`，因为这是一个**查询参数**。稍后我们还会看到 `Path()`、`Body()`、`Header()` 和 `Cookie()`，它们也接受与 `Query()` 相同的参数。

///

FastAPI 现在会：

- 对数据进行**校验**，确保最大长度为 50 个字符
- 当数据无效时向客户端展示**清晰的错误**
- 在 OpenAPI 模式的*路径操作*中**记录**该参数（因此会出现在**自动文档 UI** 中）

			if err != nil {
				err = msgp.WrapError(err)
				return
			}
		}
	}
	return
}

// EncodeMsg implements msgp.Encodable
func (z *BatchJobExpire) EncodeMsg(en *msgp.Writer) (err error) {
	// map header, size 6
	// write "APIVersion"
	err = en.Append(0x86, 0xaa, 0x41, 0x50, 0x49, 0x56, 0x65, 0x72, 0x73, 0x69, 0x6f, 0x6e)
	if err != nil {
		return
	}
	err = en.WriteString(z.APIVersion)
	if err != nil {

library".  The executable is therefore covered by this License.
Section 6 states terms for distribution of such executables.

  When a "work that uses the Library" uses material from a header file
that is part of the Library, the object code for the work may be a
derivative work of the Library even though the source code is not.
Whether this is true is especially significant if the work can be

   * @since NEXT
   */
  public long serializedSize() {
    // We return a long (and not an int) because the max serialized size is approximately
    // 17 billion bytes (2^31 * 8 bytes).

    // The serialization header is 6 bytes:
    //   1 byte for the strategy
    //   1 byte for the number of hash functions
    //   4 bytes for the array length
    return (bits.bitSize() / 8) + 6;
  }

  /**

    assertThat(request.header("Referer")).isEqualTo("foo")
    assertThat(request.body).isNull()
  }

  @Test
  fun userAgent() {
    val request = fromArgs("-A", "foo", "http://example.com").createRequest()
    assertThat(request.method).isEqualTo("GET")
    assertThat(request.url.toString()).isEqualTo("http://example.com/")
    assertThat(request.header("User-Agent")).isEqualTo("foo")

Wenn Sie Clients unterstützen müssen, die keinen `Content-Type`-Header senden, können Sie die strikte Prüfung deaktivieren, indem Sie `strict_content_type=False` setzen:

{* ../../docs_src/strict_content_type/tutorial001_py310.py hl[4] *}

Mit dieser Einstellung werden Requests ohne `Content-Type`-Header im Body als JSON geparst. Das entspricht dem Verhalten älterer FastAPI-Versionen.

/// info | Info

		}
	}
	if err != nil {
		return n, err
	}
	return n, err
}

// Write the headers into the given buffer
func (lrw *ResponseRecorder) writeHeaders(w io.Writer, statusCode int, headers http.Header) {
	n, _ := fmt.Fprintf(w, "%d %s\n", statusCode, http.StatusText(statusCode))
	lrw.headerBytesWritten += n
	for k, v := range headers {
		n, _ := fmt.Fprintf(w, "%s: %s\n", k, v[0])
		lrw.headerBytesWritten += n
	}