# 20.7. `httplib` — HTTP protocol client

注解

The `httplib` module has been renamed to `http.client` in Python 3. The 2to3 tool will automatically adapt imports when converting your sources to Python 3.

Source code: Lib/httplib.py

This module defines classes which implement the client side of the HTTP and HTTPS protocols. It is normally not used directly — the module `urllib` uses it to handle URLs that use HTTP and HTTPS.

参见

The Requests package is recommended for a higher-level HTTP client interface.

注解

HTTPS support is only available if the `socket` module was compiled with SSL support.

注解

The public interface for this module changed substantially in Python 2.0. The `HTTP` class is retained only for backward compatibility with 1.5.2. It should not be used in new code. Refer to the online docstrings for usage.

The module provides the following classes:

class `httplib.``HTTPConnection`(host[, port[, strict[, timeout[, source_address]]]])

  An `HTTPConnection` instance represents one transaction with an HTTP server. It should be instantiated passing it a host and optional port number. If no port number is passed, the port is extracted from the host string if it has the form `host:port`, else the default HTTP port (80) is used. When true, the optional parameter strict (which defaults to a false value) causes `BadStatusLine` to be raised if the status line can’t be parsed as a valid HTTP/1.0 or 1.1 status line. If the optional timeout parameter is given, blocking operations (like connection attempts) will timeout after that many seconds (if it is not given, the global default timeout setting is used). The optional source_address parameter may be a tuple of a (host, port) to use as the source address the HTTP connection is made from.

  For example, the following calls all create instances that connect to the server at the same host and port:

      >>> h1 = httplib.HTTPConnection('www.cwi.nl')
      >>> h2 = httplib.HTTPConnection('www.cwi.nl:80')
      >>> h3 = httplib.HTTPConnection('www.cwi.nl', 80)
      >>> h3 = httplib.HTTPConnection('www.cwi.nl', 80, timeout=10)

  2.0 新版功能.

  在 2.6 版更改: timeout was added.

  在 2.7 版更改: source_address was added.

class `httplib.``HTTPSConnection`(host[, port[, key_file[, cert_file[, strict[, timeout[, source_address[, context]]]]]]])

  A subclass of `HTTPConnection` that uses SSL for communication with secure servers. Default port is `443`. If context is specified, it must be a `ssl.SSLContext` instance describing the various SSL options.

  key_file and cert_file are deprecated, please use `ssl.SSLContext.load_cert_chain()` instead, or let `ssl.create_default_context()` select the system’s trusted CA certificates for you.

  Please read Security considerations for more information on best practices.

  2.0 新版功能.

  在 2.6 版更改: timeout was added.

  在 2.7 版更改: source_address was added.

  在 2.7.9 版更改: context was added.

  This class now performs all the necessary certificate and hostname checks by default. To revert to the previous, unverified, behavior `ssl._create_unverified_context()` can be passed to the context parameter.

class `httplib.``HTTPResponse`(sock, debuglevel=0, strict=0)

  Class whose instances are returned upon successful connection. Not instantiated directly by user.

  2.0 新版功能.

class `httplib.``HTTPMessage`

  An `HTTPMessage` instance is used to hold the headers from an HTTP response. It is implemented using the `mimetools.Message` class and provides utility functions to deal with HTTP Headers. It is not directly instantiated by the users.

The following exceptions are raised as appropriate:

exception `httplib.``HTTPException`

  The base class of the other exceptions in this module. It is a subclass of `Exception`.

  2.0 新版功能.

exception `httplib.``NotConnected`

  A subclass of `HTTPException`.

  2.0 新版功能.

exception `httplib.``InvalidURL`

  A subclass of `HTTPException`, raised if a port is given and is either non-numeric or empty.

  2.3 新版功能.

exception `httplib.``UnknownProtocol`

  A subclass of `HTTPException`.

  2.0 新版功能.

exception `httplib.``UnknownTransferEncoding`

  A subclass of `HTTPException`.

  2.0 新版功能.

exception `httplib.``UnimplementedFileMode`

  A subclass of `HTTPException`.

  2.0 新版功能.

exception `httplib.``IncompleteRead`

  A subclass of `HTTPException`.

  2.0 新版功能.

exception `httplib.``ImproperConnectionState`

  A subclass of `HTTPException`.

  2.0 新版功能.

exception `httplib.``CannotSendRequest`

  A subclass of `ImproperConnectionState`.

  2.0 新版功能.

exception `httplib.``CannotSendHeader`

  A subclass of `ImproperConnectionState`.

  2.0 新版功能.

exception `httplib.``ResponseNotReady`

  A subclass of `ImproperConnectionState`.

  2.0 新版功能.

exception `httplib.``BadStatusLine`

  A subclass of `HTTPException`. Raised if a server responds with a HTTP status code that we don’t understand.

  2.0 新版功能.

The constants defined in this module are:

`httplib.``HTTP_PORT`

  The default port for the HTTP protocol (always `80`).

`httplib.``HTTPS_PORT`

  The default port for the HTTPS protocol (always `443`).

and also the following constants for integer status codes:

Constant | Value | Definition
--- | --- | ---
`CONTINUE` | `100` | HTTP/1.1, RFC 2616, Section 10.1.1
`SWITCHING_PROTOCOLS` | `101` | HTTP/1.1, RFC 2616, Section 10.1.2
`PROCESSING` | `102` | WEBDAV, RFC 2518, Section 10.1
`OK` | `200` | HTTP/1.1, RFC 2616, Section 10.2.1
`CREATED` | `201` | HTTP/1.1, RFC 2616, Section 10.2.2
`ACCEPTED` | `202` | HTTP/1.1, RFC 2616, Section 10.2.3
`NON_AUTHORITATIVE_INFORMATION` | `203` | HTTP/1.1, RFC 2616, Section 10.2.4
`NO_CONTENT` | `204` | HTTP/1.1, RFC 2616, Section 10.2.5
`RESET_CONTENT` | `205` | HTTP/1.1, RFC 2616, Section 10.2.6
`PARTIAL_CONTENT` | `206` | HTTP/1.1, RFC 2616, Section 10.2.7
`MULTI_STATUS` | `207` | WEBDAV RFC 2518, Section 10.2
`IM_USED` | `226` | Delta encoding in HTTP, RFC 3229, Section 10.4.1
`MULTIPLE_CHOICES` | `300` | HTTP/1.1, RFC 2616, Section 10.3.1
`MOVED_PERMANENTLY` | `301` | HTTP/1.1, RFC 2616, Section 10.3.2
`FOUND` | `302` | HTTP/1.1, RFC 2616, Section 10.3.3
`SEE_OTHER` | `303` | HTTP/1.1, RFC 2616, Section 10.3.4
`NOT_MODIFIED` | `304` | HTTP/1.1, RFC 2616, Section 10.3.5
`USE_PROXY` | `305` | HTTP/1.1, RFC 2616, Section 10.3.6
`TEMPORARY_REDIRECT` | `307` | HTTP/1.1, RFC 2616, Section 10.3.8
`BAD_REQUEST` | `400` | HTTP/1.1, RFC 2616, Section 10.4.1
`UNAUTHORIZED` | `401` | HTTP/1.1, RFC 2616, Section 10.4.2
`PAYMENT_REQUIRED` | `402` | HTTP/1.1, RFC 2616, Section 10.4.3
`FORBIDDEN` | `403` | HTTP/1.1, RFC 2616, Section 10.4.4
`NOT_FOUND` | `404` | HTTP/1.1, RFC 2616, Section 10.4.5
`METHOD_NOT_ALLOWED` | `405` | HTTP/1.1, RFC 2616, Section 10.4.6
`NOT_ACCEPTABLE` | `406` | HTTP/1.1, RFC 2616, Section 10.4.7
`PROXY_AUTHENTICATION_REQUIRED` | `407` | HTTP/1.1, RFC 2616, Section 10.4.8
`REQUEST_TIMEOUT` | `408` | HTTP/1.1, RFC 2616, Section 10.4.9
`CONFLICT` | `409` | HTTP/1.1, RFC 2616, Section 10.4.10
`GONE` | `410` | HTTP/1.1, RFC 2616, Section 10.4.11
`LENGTH_REQUIRED` | `411` | HTTP/1.1, RFC 2616, Section 10.4.12
`PRECONDITION_FAILED` | `412` | HTTP/1.1, RFC 2616, Section 10.4.13
`REQUEST_ENTITY_TOO_LARGE` | `413` | HTTP/1.1, RFC 2616, Section 10.4.14
`REQUEST_URI_TOO_LONG` | `414` | HTTP/1.1, RFC 2616, Section 10.4.15
`UNSUPPORTED_MEDIA_TYPE` | `415` | HTTP/1.1, RFC 2616, Section 10.4.16
`REQUESTED_RANGE_NOT_SATISFIABLE` | `416` | HTTP/1.1, RFC 2616, Section 10.4.17
`EXPECTATION_FAILED` | `417` | HTTP/1.1, RFC 2616, Section 10.4.18
`UNPROCESSABLE_ENTITY` | `422` | WEBDAV, RFC 2518, Section 10.3
`LOCKED` | `423` | WEBDAV RFC 2518, Section 10.4
`FAILED_DEPENDENCY` | `424` | WEBDAV, RFC 2518, Section 10.5
`UPGRADE_REQUIRED` | `426` | HTTP Upgrade to TLS, RFC 2817, Section 6
`INTERNAL_SERVER_ERROR` | `500` | HTTP/1.1, RFC 2616, Section 10.5.1
`NOT_IMPLEMENTED` | `501` | HTTP/1.1, RFC 2616, Section 10.5.2
`BAD_GATEWAY` | `502` | HTTP/1.1 RFC 2616, Section 10.5.3
`SERVICE_UNAVAILABLE` | `503` | HTTP/1.1, RFC 2616, Section 10.5.4
`GATEWAY_TIMEOUT` | `504` | HTTP/1.1 RFC 2616, Section 10.5.5
`HTTP_VERSION_NOT_SUPPORTED` | `505` | HTTP/1.1, RFC 2616, Section 10.5.6
`INSUFFICIENT_STORAGE` | `507` | WEBDAV, RFC 2518, Section 10.6
`NOT_EXTENDED` | `510` | An HTTP Extension Framework, RFC 2774, Section 7

`httplib.``responses`

  This dictionary maps the HTTP 1.1 status codes to the W3C names.

  Example: `httplib.responses[httplib.NOT_FOUND]` is `'Not Found'`.

  2.5 新版功能.

## 20.7.1. HTTPConnection Objects

`HTTPConnection` instances have the following methods:

`HTTPConnection.``request`(method, url[, body[, headers]])

  This will send a request to the server using the HTTP request method method and the selector url. If the body argument is present, it should be a string of data to send after the headers are finished. Alternatively, it may be an open file object, in which case the contents of the file is sent; this file object should support `fileno()` and `read()` methods. The headers argument should be a mapping of extra HTTP headers to send with the request.

  If one is not provided in headers, a `Content-Length` header is added automatically for all methods if the length of the body can be determined, either from the length of the `str` representation, or from the reported size of the file on disk. If body is `None` the header is not set except for methods that expect a body (`PUT`, `POST`, and `PATCH`) in which case it is set to `0`.

  在 2.6 版更改: body can be a file object.

`HTTPConnection.``getresponse`()

  Should be called after a request is sent to get the response from the server. Returns an `HTTPResponse` instance.

  注解

  Note that you must have read the whole response before you can send a new request to the server.

`HTTPConnection.``set_debuglevel`(level)

  Set the debugging level (the amount of debugging output printed). The default debug level is `0`, meaning no debugging output is printed.

`HTTPConnection.``set_tunnel`(host, port=None, headers=None)

  Set the host and the port for HTTP Connect Tunnelling. Normally used when it is required to do HTTPS Connection through a proxy server.

  The headers argument should be a mapping of extra HTTP headers to send with the CONNECT request.

  2.7 新版功能.

`HTTPConnection.``connect`()

  Connect to the server specified when the object was created.

`HTTPConnection.``close`()

  Close the connection to the server.

As an alternative to using the `request()` method described above, you can also send your request step by step, by using the four functions below.

`HTTPConnection.``putrequest`(request, selector[, skip_host[, skip_accept_encoding]])

  This should be the first call after the connection to the server has been made. It sends a line to the server consisting of the request string, the selector string, and the HTTP version (`HTTP/1.1`). To disable automatic sending of `Host:` or `Accept-Encoding:` headers (for example to accept additional content encodings), specify skip_host or skip_accept_encoding with non-False values.

  在 2.4 版更改: skip_accept_encoding argument added.

`HTTPConnection.``putheader`(header, argument[, ...])

  Send an RFC 822-style header to the server. It sends a line to the server consisting of the header, a colon and a space, and the first argument. If more arguments are given, continuation lines are sent, each consisting of a tab and an argument.

`HTTPConnection.``endheaders`(message_body=None)

  Send a blank line to the server, signalling the end of the headers. The optional message_body argument can be used to pass a message body associated with the request. The message body will be sent in the same packet as the message headers if it is string, otherwise it is sent in a separate packet.

  在 2.7 版更改: message_body was added.

`HTTPConnection.``send`(data)

  Send data to the server. This should be used directly only after the `endheaders()` method has been called and before `getresponse()` is called.

## 20.7.2. HTTPResponse Objects

`HTTPResponse` instances have the following methods and attributes:

`HTTPResponse.``read`([amt])

  Reads and returns the response body, or up to the next amt bytes.

`HTTPResponse.``getheader`(name[, default])

  Get the contents of the header name, or default if there is no matching header.

`HTTPResponse.``getheaders`()

  Return a list of (header, value) tuples.

  2.4 新版功能.

`HTTPResponse.``fileno`()

  Returns the `fileno` of the underlying socket.

`HTTPResponse.``msg`

  A `mimetools.Message` instance containing the response headers.

`HTTPResponse.``version`

  HTTP protocol version used by server. 10 for HTTP/1.0, 11 for HTTP/1.1.

`HTTPResponse.``status`

  Status code returned by server.

`HTTPResponse.``reason`

  Reason phrase returned by server.

## 20.7.3. Examples

Here is an example session that uses the `GET` method:

    >>> import httplib
    >>> conn = httplib.HTTPSConnection("www.python.org")
    >>> conn.request("GET", "/")
    >>> r1 = conn.getresponse()
    >>> print r1.status, r1.reason
    200 OK
    >>> data1 = r1.read()
    >>> conn.request("GET", "/")
    >>> r2 = conn.getresponse()
    >>> print r2.status, r2.reason
    404 Not Found
    >>> data2 = r2.read()
    >>> conn.close()

Here is an example session that uses the `HEAD` method. Note that the `HEAD` method never returns any data.

    >>> import httplib
    >>> conn = httplib.HTTPSConnection("www.python.org")
    >>> conn.request("HEAD","/")
    >>> res = conn.getresponse()
    >>> print res.status, res.reason
    200 OK
    >>> data = res.read()
    >>> print len(data)
    0
    >>> data == ''
    True

Here is an example session that shows how to `POST` requests:

    >>> import httplib, urllib
    >>> params = urllib.urlencode({'@number': 12524, '@type': 'issue', '@action': 'show'})
    >>> headers = {"Content-type": "application/x-www-form-urlencoded",
    ...            "Accept": "text/plain"}
    >>> conn = httplib.HTTPConnection("bugs.python.org")
    >>> conn.request("POST", "", params, headers)
    >>> response = conn.getresponse()
    >>> print response.status, response.reason
    302 Found
    >>> data = response.read()
    >>> data
    'Redirecting to <a href="http://bugs.python.org/issue12524">http://bugs.python.org/issue12524</a>'
    >>> conn.close()

Client side `HTTP PUT` requests are very similar to `POST` requests. The difference lies only the server side where HTTP server will allow resources to be created via `PUT` request. Here is an example session that shows how to do `PUT` request using httplib:

    >>> # This creates an HTTP message
    >>> # with the content of BODY as the enclosed representation
    >>> # for the resource http://localhost:8080/foobar
    ...
    >>> import httplib
    >>> BODY = "***filecontents***"
    >>> conn = httplib.HTTPConnection("localhost", 8080)
    >>> conn.request("PUT", "/file", BODY)
    >>> response = conn.getresponse()
    >>> print response.status, response.reason
    200, OK