cpython/Doc/library/http.client.rst
R. David Murray 43b2f457a0 Merged revisions 87136,87221,87256,87337-87338,87571,87839,88164 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k


........
  r87136 | r.david.murray | 2010-12-08 17:53:00 -0500 (Wed, 08 Dec 2010) | 6 lines

  Have script_helper._assert_python strip refcount strings from stderr.

  This makes the output of the function and those that depend on it
  independent of whether or not they are being run under a debug
  build.
........
  r87221 | r.david.murray | 2010-12-13 19:55:46 -0500 (Mon, 13 Dec 2010) | 4 lines

  #10699: fix docstring for tzset: it does not take a parameter

  Thanks to Garrett Cooper for the fix.
........
  r87256 | r.david.murray | 2010-12-14 21:19:14 -0500 (Tue, 14 Dec 2010) | 2 lines

  #10705: document what the values of debuglevel are and mean.
........
  r87337 | r.david.murray | 2010-12-17 11:11:40 -0500 (Fri, 17 Dec 2010) | 2 lines

  #10559: provide instructions for accessing sys.argv when first mentioned.
........
  r87338 | r.david.murray | 2010-12-17 11:29:07 -0500 (Fri, 17 Dec 2010) | 2 lines

  #10454: clarify the compileall docs and help messages.
    [compileall.py changes not backported.]
........
  r87571 | r.david.murray | 2010-12-29 14:06:48 -0500 (Wed, 29 Dec 2010) | 2 lines

  Fix same typo in docs.
........
  r87839 | r.david.murray | 2011-01-07 16:57:25 -0500 (Fri, 07 Jan 2011) | 9 lines

  Fix formatting of values with embedded newlines when rfc2047 encoding

  Before this patch if a value being encoded had an embedded newline,
  the line following the newline would have no leading whitespace,
  and the whitespace it did have was encoded into the word.  Now
  the existing whitespace gets turned into a blank, the way it does
  in other header reformatting, and the _continuation_ws gets added
  at the beginning of the encoded line.
........
  r88164 | r.david.murray | 2011-01-24 14:34:58 -0500 (Mon, 24 Jan 2011) | 12 lines

  #10960: fix 'stat' links, link to lstat from stat, general tidy of stat doc.

  Original patch by Michal Nowikowski, with some additions and wording
  fixes by me.

  I changed the wording from 'Performs a stat system call' to 'Performs
  the equivalent of a stat system call', since on Windows there are no
  stat/lstat system calls involved.  I also extended Michal's breakout
  of the attributes into a list to the other paragraphs, and rearranged
  the order of the paragraphs in the 'stat' docs to make it flow
  better and put it in what I think is a more logical/useful order.
........
2011-02-11 03:13:19 +00:00

605 lines
36 KiB
ReStructuredText

:mod:`http.client` --- HTTP protocol client
===========================================
.. module:: http.client
:synopsis: HTTP and HTTPS protocol client (requires sockets).
.. index::
pair: HTTP; protocol
single: HTTP; http.client (standard module)
.. index:: module: urllib.request
**Source code:** :source:`Lib/http/client.py`
--------------
This module defines classes which implement the client side of the HTTP and
HTTPS protocols. It is normally not used directly --- the module
:mod:`urllib.request` uses it to handle URLs that use HTTP and HTTPS.
.. note::
HTTPS support is only available if Python was compiled with SSL support
(through the :mod:`ssl` module).
The module provides the following classes:
.. class:: HTTPConnection(host, port=None[, strict[, timeout[, source_address]]])
An :class:`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. 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 = http.client.HTTPConnection('www.cwi.nl')
>>> h2 = http.client.HTTPConnection('www.cwi.nl:80')
>>> h3 = http.client.HTTPConnection('www.cwi.nl', 80)
>>> h3 = http.client.HTTPConnection('www.cwi.nl', 80, timeout=10)
.. versionchanged:: 3.2
*source_address* was added.
.. versionchanged:: 3.2
The *strict* parameter is deprecated. HTTP 0.9-style "Simple Responses"
are not supported anymore.
.. class:: HTTPSConnection(host, port=None, key_file=None, cert_file=None[, strict[, timeout[, source_address]]], *, context=None, check_hostname=None)
A subclass of :class:`HTTPConnection` that uses SSL for communication with
secure servers. Default port is ``443``. If *context* is specified, it
must be a :class:`ssl.SSLContext` instance describing the various SSL
options. If *context* is specified and has a :attr:`~ssl.SSLContext.verify_mode`
of either :data:`~ssl.CERT_OPTIONAL` or :data:`~ssl.CERT_REQUIRED`, then
by default *host* is matched against the host name(s) allowed by the
server's certificate. If you want to change that behaviour, you can
explicitly set *check_hostname* to False.
*key_file* and *cert_file* are deprecated, please use
:meth:`ssl.SSLContext.load_cert_chain` instead.
If you access arbitrary hosts on the Internet, it is recommended to
require certificate checking and feed the *context* with a set of
trusted CA certificates::
context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
context.verify_mode = ssl.CERT_REQUIRED
context.load_verify_locations('/etc/pki/tls/certs/ca-bundle.crt')
h = client.HTTPSConnection('svn.python.org', 443, context=context)
.. versionchanged:: 3.2
*source_address*, *context* and *check_hostname* were added.
.. versionchanged:: 3.2
This class now supports HTTPS virtual hosts if possible (that is,
if :data:`ssl.HAS_SNI` is true).
.. versionchanged:: 3.2
The *strict* parameter is deprecated. HTTP 0.9-style "Simple Responses"
are not supported anymore.
.. class:: HTTPResponse(sock, debuglevel=0[, strict], method=None, url=None)
Class whose instances are returned upon successful connection. Not
instantiated directly by user.
.. versionchanged:: 3.2
The *strict* parameter is deprecated. HTTP 0.9-style "Simple Responses"
are not supported anymore.
The following exceptions are raised as appropriate:
.. exception:: HTTPException
The base class of the other exceptions in this module. It is a subclass of
:exc:`Exception`.
.. exception:: NotConnected
A subclass of :exc:`HTTPException`.
.. exception:: InvalidURL
A subclass of :exc:`HTTPException`, raised if a port is given and is either
non-numeric or empty.
.. exception:: UnknownProtocol
A subclass of :exc:`HTTPException`.
.. exception:: UnknownTransferEncoding
A subclass of :exc:`HTTPException`.
.. exception:: UnimplementedFileMode
A subclass of :exc:`HTTPException`.
.. exception:: IncompleteRead
A subclass of :exc:`HTTPException`.
.. exception:: ImproperConnectionState
A subclass of :exc:`HTTPException`.
.. exception:: CannotSendRequest
A subclass of :exc:`ImproperConnectionState`.
.. exception:: CannotSendHeader
A subclass of :exc:`ImproperConnectionState`.
.. exception:: ResponseNotReady
A subclass of :exc:`ImproperConnectionState`.
.. exception:: BadStatusLine
A subclass of :exc:`HTTPException`. Raised if a server responds with a HTTP
status code that we don't understand.
The constants defined in this module are:
.. data:: HTTP_PORT
The default port for the HTTP protocol (always ``80``).
.. data:: HTTPS_PORT
The default port for the HTTPS protocol (always ``443``).
and also the following constants for integer status codes:
+------------------------------------------+---------+-----------------------------------------------------------------------+
| Constant | Value | Definition |
+==========================================+=========+=======================================================================+
| :const:`CONTINUE` | ``100`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.1.1 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.1.1>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`SWITCHING_PROTOCOLS` | ``101`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.1.2 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.1.2>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`PROCESSING` | ``102`` | WEBDAV, `RFC 2518, Section 10.1 |
| | | <http://www.webdav.org/specs/rfc2518.html#STATUS_102>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`OK` | ``200`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.2.1 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.1>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`CREATED` | ``201`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.2.2 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.2>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`ACCEPTED` | ``202`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.2.3 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.3>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`NON_AUTHORITATIVE_INFORMATION` | ``203`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.2.4 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.4>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`NO_CONTENT` | ``204`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.2.5 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.5>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`RESET_CONTENT` | ``205`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.2.6 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.6>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`PARTIAL_CONTENT` | ``206`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.2.7 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.7>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`MULTI_STATUS` | ``207`` | WEBDAV `RFC 2518, Section 10.2 |
| | | <http://www.webdav.org/specs/rfc2518.html#STATUS_207>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`IM_USED` | ``226`` | Delta encoding in HTTP, |
| | | :rfc:`3229`, Section 10.4.1 |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`MULTIPLE_CHOICES` | ``300`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.3.1 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.1>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`MOVED_PERMANENTLY` | ``301`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.3.2 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.2>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`FOUND` | ``302`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.3.3 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.3>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`SEE_OTHER` | ``303`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.3.4 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.4>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`NOT_MODIFIED` | ``304`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.3.5 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.5>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`USE_PROXY` | ``305`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.3.6 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.6>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`TEMPORARY_REDIRECT` | ``307`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.3.8 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.8>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`BAD_REQUEST` | ``400`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.1 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.1>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`UNAUTHORIZED` | ``401`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.2 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.2>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`PAYMENT_REQUIRED` | ``402`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.3 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.3>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`FORBIDDEN` | ``403`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.4 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.4>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`NOT_FOUND` | ``404`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.5 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.5>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`METHOD_NOT_ALLOWED` | ``405`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.6 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.6>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`NOT_ACCEPTABLE` | ``406`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.7 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.7>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`PROXY_AUTHENTICATION_REQUIRED` | ``407`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.8 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.8>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`REQUEST_TIMEOUT` | ``408`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.9 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.9>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`CONFLICT` | ``409`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.10 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.10>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`GONE` | ``410`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.11 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.11>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`LENGTH_REQUIRED` | ``411`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.12 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.12>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`PRECONDITION_FAILED` | ``412`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.13 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.13>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`REQUEST_ENTITY_TOO_LARGE` | ``413`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.14 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.14>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`REQUEST_URI_TOO_LONG` | ``414`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.15 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.15>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`UNSUPPORTED_MEDIA_TYPE` | ``415`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.16 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.16>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`REQUESTED_RANGE_NOT_SATISFIABLE` | ``416`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.17 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.17>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`EXPECTATION_FAILED` | ``417`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.4.18 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.18>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`UNPROCESSABLE_ENTITY` | ``422`` | WEBDAV, `RFC 2518, Section 10.3 |
| | | <http://www.webdav.org/specs/rfc2518.html#STATUS_422>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`LOCKED` | ``423`` | WEBDAV `RFC 2518, Section 10.4 |
| | | <http://www.webdav.org/specs/rfc2518.html#STATUS_423>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`FAILED_DEPENDENCY` | ``424`` | WEBDAV, `RFC 2518, Section 10.5 |
| | | <http://www.webdav.org/specs/rfc2518.html#STATUS_424>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`UPGRADE_REQUIRED` | ``426`` | HTTP Upgrade to TLS, |
| | | :rfc:`2817`, Section 6 |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`INTERNAL_SERVER_ERROR` | ``500`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.5.1 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.1>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`NOT_IMPLEMENTED` | ``501`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.5.2 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.2>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`BAD_GATEWAY` | ``502`` | HTTP/1.1 `RFC 2616, Section |
| | | 10.5.3 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.3>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`SERVICE_UNAVAILABLE` | ``503`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.5.4 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.4>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`GATEWAY_TIMEOUT` | ``504`` | HTTP/1.1 `RFC 2616, Section |
| | | 10.5.5 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.5>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`HTTP_VERSION_NOT_SUPPORTED` | ``505`` | HTTP/1.1, `RFC 2616, Section |
| | | 10.5.6 |
| | | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.6>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`INSUFFICIENT_STORAGE` | ``507`` | WEBDAV, `RFC 2518, Section 10.6 |
| | | <http://www.webdav.org/specs/rfc2518.html#STATUS_507>`_ |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`NOT_EXTENDED` | ``510`` | An HTTP Extension Framework, |
| | | :rfc:`2774`, Section 7 |
+------------------------------------------+---------+-----------------------------------------------------------------------+
.. data:: responses
This dictionary maps the HTTP 1.1 status codes to the W3C names.
Example: ``http.client.responses[http.client.NOT_FOUND]`` is ``'Not Found'``.
.. _httpconnection-objects:
HTTPConnection Objects
----------------------
:class:`HTTPConnection` instances have the following methods:
.. method:: HTTPConnection.request(method, url, body=None, 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 string or bytes object of data to send after
the headers are finished. Strings are encoded as ISO-8859-1, the
default charset for HTTP. To use other encodings, pass a bytes
object. The Content-Length header is set to the length of the
string.
The *body* may also be an open :term:`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 length of the file as reported by stat. The *body* argument may also be
an iterable and Content-Length header should be explicitly provided when the
body is an iterable.
The *headers* argument should be a mapping of extra HTTP
headers to send with the request.
.. versionadded:: 3.2
*body* can now be an iterable.
.. method:: HTTPConnection.getresponse()
Should be called after a request is sent to get the response from the server.
Returns an :class:`HTTPResponse` instance.
.. note::
Note that you must have read the whole response before you can send a new
request to the server.
.. method:: HTTPConnection.set_debuglevel(level)
Set the debugging level. The default debug level is ``0``, meaning no
debugging output is printed. Any value greater than ``0`` will cause all
currently defined debug output to be printed to stdout. The ``debuglevel``
is passed to any new :class:`HTTPResponse` objects that are created.
.. versionadded:: 3.1
.. method:: 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 a HTTPS Connection through a proxy server.
The headers argument should be a mapping of extra HTTP headers to to sent
with the CONNECT request.
.. versionadded:: 3.2
.. method:: HTTPConnection.connect()
Connect to the server specified when the object was created.
.. method:: HTTPConnection.close()
Close the connection to the server.
As an alternative to using the :meth:`request` method described above, you can
also send your request step by step, by using the four functions below.
.. method:: HTTPConnection.putrequest(request, selector, skip_host=False, skip_accept_encoding=False)
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.
.. method:: 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.
.. method:: HTTPConnection.endheaders()
Send a blank line to the server, signalling the end of the headers.
.. method:: HTTPConnection.send(data)
Send data to the server. This should be used directly only after the
:meth:`endheaders` method has been called and before :meth:`getresponse` is
called.
.. _httpresponse-objects:
HTTPResponse Objects
--------------------
An :class:`HTTPResponse` instance wraps the HTTP response from the
server. It provides access to the request headers and the entity
body. The response is an iterable object and can be used in a with
statement.
.. method:: HTTPResponse.read([amt])
Reads and returns the response body, or up to the next *amt* bytes.
.. method:: HTTPResponse.getheader(name, default=None)
Return the value of the header *name*, or *default* if there is no header
matching *name*. If there is more than one header with the name *name*,
return all of the values joined by ', '. If 'default' is any iterable other
than a single string, its elements are similarly returned joined by commas.
.. method:: HTTPResponse.getheaders()
Return a list of (header, value) tuples.
.. method:: HTTPResponse.fileno()
Return the ``fileno`` of the underlying socket.
.. attribute:: HTTPResponse.msg
A :class:`http.client.HTTPMessage` instance containing the response
headers. :class:`http.client.HTTPMessage` is a subclass of
:class:`email.message.Message`.
.. attribute:: HTTPResponse.version
HTTP protocol version used by server. 10 for HTTP/1.0, 11 for HTTP/1.1.
.. attribute:: HTTPResponse.status
Status code returned by server.
.. attribute:: HTTPResponse.reason
Reason phrase returned by server.
.. attribute:: HTTPResponse.debuglevel
A debugging hook. If :attr:`debuglevel` is greater than zero, messages
will be printed to stdout as the response is read and parsed.
Examples
--------
Here is an example session that uses the ``GET`` method::
>>> import http.client
>>> conn = http.client.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 http.client
>>> conn = http.client.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 == b''
True
Here is an example session that shows how to ``POST`` requests::
>>> import http.client, urllib.parse
>>> params = urllib.parse.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0})
>>> headers = {"Content-type": "application/x-www-form-urlencoded",
... "Accept": "text/plain"}
>>> conn = http.client.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()
.. _httpmessage-objects:
HTTPMessage Objects
-------------------
An :class:`http.client.HTTPMessage` instance holds the headers from an HTTP
response. It is implemented using the :class:`email.message.Message` class.
.. XXX Define the methods that clients can depend upon between versions.