"http" --- HTTP モジュール群
****************************

**ソースコード:** Lib/http/__init__.py

======================================================================

"http" パッケージはハイパーテキスト転送プロトコルを扱うための幾つかの
モジュールを集めたものです:

* "http.client" は低水準のHTTPプロトコルのクライアントです。高水準の
  URL を開く操作には "urllib.request" を使ってください

* "http.server" は "socketserver" をベースにした基礎的な HTTP サーバー
  を実装しています

* "http.cookies" は cookie の状態管理を実装するためのユーティリティー
  を提供しています

* "http.cookiejar" は cookie の永続化機能を提供しています

"http" は "http.HTTPStatus" 列挙子で 多くの HTTP ステータスコードと関
連するメッセージを定義しているモジュールでもあります。

class http.HTTPStatus

   バージョン 3.5 で追加.

   一連の HTTP ステータスコード、理由の表現、英語で書かれた長い記述を
   定義した "enum.IntEnum" のサブクラスです。

   使い方:

      >>> from http import HTTPStatus
      >>> HTTPStatus.OK
      <HTTPStatus.OK: 200>
      >>> HTTPStatus.OK == 200
      True
      >>> HTTPStatus.OK.value
      200
      >>> HTTPStatus.OK.phrase
      'OK'
      >>> HTTPStatus.OK.description
      'Request fulfilled, document follows'
      >>> list(HTTPStatus)
      [<HTTPStatus.CONTINUE: 100>, <HTTPStatus.SWITCHING_PROTOCOLS: 101>, ...]


HTTP ステータスコード
=====================

サポートされている IANA に登録された "http.HTTPStatus" で利用可能なス
テータスコード:

+---------+-------------------------------------+---------------------------------------------------------------------------------+
| コード  | 列挙名                              | 詳細                                                                            |
|=========|=====================================|=================================================================================|
| "100"   | "CONTINUE"                          | HTTP/1.1 **RFC 7231**, Section 6.2.1                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "101"   | "SWITCHING_PROTOCOLS"               | HTTP/1.1 **RFC 7231**, Section 6.2.2                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "102"   | "PROCESSING"                        | WebDAV **RFC 2518**, Section 10.1                                               |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "103"   | "EARLY_HINTS"                       | An HTTP Status Code for Indicating Hints **RFC 8297**                           |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "200"   | "OK"                                | HTTP/1.1 **RFC 7231**, Section 6.3.1                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "201"   | "CREATED"                           | HTTP/1.1 **RFC 7231**, Section 6.3.2                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "202"   | "ACCEPTED"                          | HTTP/1.1 **RFC 7231**, Section 6.3.3                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "203"   | "NON_AUTHORITATIVE_INFORMATION"     | HTTP/1.1 **RFC 7231**, Section 6.3.4                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "204"   | "NO_CONTENT"                        | HTTP/1.1 **RFC 7231**, Section 6.3.5                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "205"   | "RESET_CONTENT"                     | HTTP/1.1 **RFC 7231**, Section 6.3.6                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "206"   | "PARTIAL_CONTENT"                   | HTTP/1.1 **RFC 7233**, Section 4.1                                              |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "207"   | "MULTI_STATUS"                      | WebDAV **RFC 4918**, Section 11.1                                               |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "208"   | "ALREADY_REPORTED"                  | WebDAV Binding Extensions **RFC 5842**, Section 7.1 (Experimental)              |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "226"   | "IM_USED"                           | Delta Encoding in HTTP **RFC 3229**, Section 10.4.1                             |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "300"   | "MULTIPLE_CHOICES"                  | HTTP/1.1 **RFC 7231**, Section 6.4.1                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "301"   | "MOVED_PERMANENTLY"                 | HTTP/1.1 **RFC 7231**, Section 6.4.2                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "302"   | "FOUND"                             | HTTP/1.1 **RFC 7231**, Section 6.4.3                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "303"   | "SEE_OTHER"                         | HTTP/1.1 **RFC 7231**, Section 6.4.4                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "304"   | "NOT_MODIFIED"                      | HTTP/1.1 **RFC 7232**, Section 4.1                                              |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "305"   | "USE_PROXY"                         | HTTP/1.1 **RFC 7231**, Section 6.4.5                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "307"   | "TEMPORARY_REDIRECT"                | HTTP/1.1 **RFC 7231**, Section 6.4.7                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "308"   | "PERMANENT_REDIRECT"                | Permanent Redirect **RFC 7238**, Section 3 (Experimental)                       |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "400"   | "BAD_REQUEST"                       | HTTP/1.1 **RFC 7231**, Section 6.5.1                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "401"   | "UNAUTHORIZED"                      | HTTP/1.1 Authentication **RFC 7235**, Section 3.1                               |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "402"   | "PAYMENT_REQUIRED"                  | HTTP/1.1 **RFC 7231**, Section 6.5.2                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "403"   | "FORBIDDEN"                         | HTTP/1.1 **RFC 7231**, Section 6.5.3                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "404"   | "NOT_FOUND"                         | HTTP/1.1 **RFC 7231**, Section 6.5.4                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "405"   | "METHOD_NOT_ALLOWED"                | HTTP/1.1 **RFC 7231**, Section 6.5.5                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "406"   | "NOT_ACCEPTABLE"                    | HTTP/1.1 **RFC 7231**, Section 6.5.6                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "407"   | "PROXY_AUTHENTICATION_REQUIRED"     | HTTP/1.1 Authentication **RFC 7235**, Section 3.2                               |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "408"   | "REQUEST_TIMEOUT"                   | HTTP/1.1 **RFC 7231**, Section 6.5.7                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "409"   | "CONFLICT"                          | HTTP/1.1 **RFC 7231**, Section 6.5.8                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "410"   | "GONE"                              | HTTP/1.1 **RFC 7231**, Section 6.5.9                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "411"   | "LENGTH_REQUIRED"                   | HTTP/1.1 **RFC 7231**, Section 6.5.10                                           |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "412"   | "PRECONDITION_FAILED"               | HTTP/1.1 **RFC 7232**, Section 4.2                                              |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "413"   | "REQUEST_ENTITY_TOO_LARGE"          | HTTP/1.1 **RFC 7231**, Section 6.5.11                                           |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "414"   | "REQUEST_URI_TOO_LONG"              | HTTP/1.1 **RFC 7231**, Section 6.5.12                                           |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "415"   | "UNSUPPORTED_MEDIA_TYPE"            | HTTP/1.1 **RFC 7231**, Section 6.5.13                                           |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "416"   | "REQUESTED_RANGE_NOT_SATISFIABLE"   | HTTP/1.1 Range Requests **RFC 7233**, Section 4.4                               |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "417"   | "EXPECTATION_FAILED"                | HTTP/1.1 **RFC 7231**, Section 6.5.14                                           |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "418"   | "IM_A_TEAPOT"                       | HTCPCP/1.0 **RFC 2324**, Section 2.3.2                                          |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "421"   | "MISDIRECTED_REQUEST"               | HTTP/2 **RFC 7540**, Section 9.1.2                                              |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "422"   | "UNPROCESSABLE_ENTITY"              | WebDAV **RFC 4918**, Section 11.2                                               |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "423"   | "LOCKED"                            | WebDAV **RFC 4918**, Section 11.3                                               |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "424"   | "FAILED_DEPENDENCY"                 | WebDAV **RFC 4918**, Section 11.4                                               |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "425"   | "TOO_EARLY"                         | Using Early Data in HTTP **RFC 8470**                                           |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "426"   | "UPGRADE_REQUIRED"                  | HTTP/1.1 **RFC 7231**, Section 6.5.15                                           |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "428"   | "PRECONDITION_REQUIRED"             | Additional HTTP Status Codes **RFC 6585**                                       |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "429"   | "TOO_MANY_REQUESTS"                 | Additional HTTP Status Codes **RFC 6585**                                       |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "431"   | "REQUEST_HEADER_FIELDS_TOO_LARGE"   | Additional HTTP Status Codes **RFC 6585**                                       |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "451"   | "UNAVAILABLE_FOR_LEGAL_REASONS"     | An HTTP Status Code to Report Legal Obstacles **RFC 7725**                      |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "500"   | "INTERNAL_SERVER_ERROR"             | HTTP/1.1 **RFC 7231**, Section 6.6.1                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "501"   | "NOT_IMPLEMENTED"                   | HTTP/1.1 **RFC 7231**, Section 6.6.2                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "502"   | "BAD_GATEWAY"                       | HTTP/1.1 **RFC 7231**, Section 6.6.3                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "503"   | "SERVICE_UNAVAILABLE"               | HTTP/1.1 **RFC 7231**, Section 6.6.4                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "504"   | "GATEWAY_TIMEOUT"                   | HTTP/1.1 **RFC 7231**, Section 6.6.5                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "505"   | "HTTP_VERSION_NOT_SUPPORTED"        | HTTP/1.1 **RFC 7231**, Section 6.6.6                                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "506"   | "VARIANT_ALSO_NEGOTIATES"           | Transparent Content Negotiation in HTTP **RFC 2295**, Section 8.1               |
|         |                                     | (Experimental)                                                                  |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "507"   | "INSUFFICIENT_STORAGE"              | WebDAV **RFC 4918**, Section 11.5                                               |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "508"   | "LOOP_DETECTED"                     | WebDAV Binding Extensions **RFC 5842**, Section 7.2 (Experimental)              |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "510"   | "NOT_EXTENDED"                      | An HTTP Extension Framework **RFC 2774**, Section 7 (Experimental)              |
+---------+-------------------------------------+---------------------------------------------------------------------------------+
| "511"   | "NETWORK_AUTHENTICATION_REQUIRED"   | Additional HTTP Status Codes **RFC 6585**, Section 6                            |
+---------+-------------------------------------+---------------------------------------------------------------------------------+

後方互換性を保つために列挙値は "http.client" にも定数という形で存在し
ます。 列挙名は定数名と同じです (すなわち "http.HTTPStatus.OK" は
"http.client.OK" としても利用可能です)。

バージョン 3.7 で変更: ステータスコード "421 MISDIRECTED_REQUEST" が追
加されました。

バージョン 3.8 で追加: ステータスコード "451
UNAVAILABLE_FOR_LEGAL_REASONS" が追加されました。

バージョン 3.9 で追加: ステータスコード "103 EARLY_HINTS", "418
IM_A_TEAPOT", "425 TOO_EARLY" が追加されました。
