
``httplib`` --- HTTP protocol client
************************************

Note: The ``httplib`` module has been renamed to ``http.client`` in Python
  3.0.  The *2to3* tool will automatically adapt imports when
  converting your sources to 3.0.

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.

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

Note: 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 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)

   New in version 2.0.

   Changed in version 2.6: *timeout* was added.

   Changed in version 2.7: *source_address* was added.

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

   A subclass of ``HTTPConnection`` that uses SSL for communication
   with secure servers.  Default port is ``443``. *key_file* is the
   name of a PEM formatted file that contains your private key.
   *cert_file* is a PEM formatted certificate chain file.

   Warning: This does not do any verification of the server's certificate.

   New in version 2.0.

   Changed in version 2.6: *timeout* was added.

   Changed in version 2.7: *source_address* was added.

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

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

   New in version 2.0.

class 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 exception httplib.HTTPException

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

   New in version 2.0.

exception exception httplib.NotConnected

   A subclass of ``HTTPException``.

   New in version 2.0.

exception exception httplib.InvalidURL

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

   New in version 2.3.

exception exception httplib.UnknownProtocol

   A subclass of ``HTTPException``.

   New in version 2.0.

exception exception httplib.UnknownTransferEncoding

   A subclass of ``HTTPException``.

   New in version 2.0.

exception exception httplib.UnimplementedFileMode

   A subclass of ``HTTPException``.

   New in version 2.0.

exception exception httplib.IncompleteRead

   A subclass of ``HTTPException``.

   New in version 2.0.

exception exception httplib.ImproperConnectionState

   A subclass of ``HTTPException``.

   New in version 2.0.

exception exception httplib.CannotSendRequest

   A subclass of ``ImproperConnectionState``.

   New in version 2.0.

exception exception httplib.CannotSendHeader

   A subclass of ``ImproperConnectionState``.

   New in version 2.0.

exception exception httplib.ResponseNotReady

   A subclass of ``ImproperConnectionState``.

   New in version 2.0.

exception exception httplib.BadStatusLine

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

   New in version 2.0.

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'``.

   New in version 2.5.


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 header
   Content-Length is automatically set to the correct value. The
   *headers* argument should be a mapping of extra HTTP headers to
   send with the request.

   Changed in version 2.6: *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.

   Note: 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 Conection through a proxy
   server.

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

   New in version 2.7.

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.

   Changed in version 2.4: *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()

   Send a blank line to the server, signalling the end of the headers.

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.


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.

   New in version 2.4.

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.


Examples
========

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

   >>> import httplib
   >>> conn = httplib.HTTPConnection("www.python.org")
   >>> conn.request("GET", "/index.html")
   >>> r1 = conn.getresponse()
   >>> print r1.status, r1.reason
   200 OK
   >>> data1 = r1.read()
   >>> conn.request("GET", "/parrot.spam")
   >>> 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.HTTPConnection("www.python.org")
   >>> conn.request("HEAD","/index.html")
   >>> 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({'spam': 1, 'eggs': 2, 'bacon': 0})
   >>> headers = {"Content-type": "application/x-www-form-urlencoded",
   ...            "Accept": "text/plain"}
   >>> conn = httplib.HTTPConnection("musi-cal.mojam.com:80")
   >>> conn.request("POST", "/cgi-bin/query", params, headers)
   >>> response = conn.getresponse()
   >>> print response.status, response.reason
   200 OK
   >>> data = response.read()
   >>> conn.close()
