Staging
v0.5.1
v0.5.1
https://github.com/python/cpython
Tip revision: dbb126103e1c4f2818e0dfc7aa4a689d86565e7a authored by Larry Hastings on 06 October 2014, 02:05:50 UTC
Release bump for 3.4.2 final.
Release bump for 3.4.2 final.
Tip revision: dbb1261
http.client.rst
: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[, timeout], \
source_address=None)
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.python.org')
>>> h2 = http.client.HTTPConnection('www.python.org:80')
>>> h3 = http.client.HTTPConnection('www.python.org', 80)
>>> h4 = http.client.HTTPConnection('www.python.org', 80, timeout=10)
.. versionchanged:: 3.2
*source_address* was added.
.. versionchanged:: 3.4
The *strict* parameter was removed. HTTP 0.9-style "Simple Responses" are
not longer supported.
.. class:: HTTPSConnection(host, port=None, key_file=None, \
cert_file=None[, timeout], \
source_address=None, *, 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.
*key_file* and *cert_file* are deprecated, please use
:meth:`ssl.SSLContext.load_cert_chain` instead, or let
:func:`ssl.create_default_context` select the system's trusted CA
certificates for you.
The recommended way to connect to HTTPS hosts on the Internet is as
follows::
context = ssl.create_default_context()
h = client.HTTPSConnection('www.python.org', 443, context=context)
Please read :ref:`ssl-security` for more information on best practices.
.. note::
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.
.. 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:: 3.4
The *strict* parameter was removed. HTTP 0.9-style "Simple Responses" are
no longer supported.
.. class:: HTTPResponse(sock, debuglevel=0, method=None, url=None)
Class whose instances are returned upon successful connection. Not
instantiated directly by user.
.. versionchanged:: 3.4
The *strict* parameter was removed. HTTP 0.9 style "Simple Responses" are
no longer supported.
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:`PRECONDITION_REQUIRED` | ``428`` | Additional HTTP Status Codes, |
| | | :rfc:`6585`, Section 3 |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`TOO_MANY_REQUESTS` | ``429`` | Additional HTTP Status Codes, |
| | | :rfc:`6585`, Section 4 |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`REQUEST_HEADER_FIELDS_TOO_LARGE` | ``431`` | Additional HTTP Status Codes, |
| | | :rfc:`6585`, Section 5 |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :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 |
+------------------------------------------+---------+-----------------------------------------------------------------------+
| :const:`NETWORK_AUTHENTICATION_REQUIRED` | ``511`` | Additional HTTP Status Codes, |
| | | :rfc:`6585`, Section 6 |
+------------------------------------------+---------+-----------------------------------------------------------------------+
.. versionchanged:: 3.3
Added codes ``428``, ``429``, ``431`` and ``511`` from :rfc:`6585`.
.. 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. This allows running
the connection through a proxy server.
The host and port arguments specify the endpoint of the tunneled connection
(i.e. the address included in the CONNECT request, *not* the address of the
proxy server).
The headers argument should be a mapping of extra HTTP headers to send with
the CONNECT request.
For example, to tunnel through a HTTPS proxy server running locally on port
8080, we would pass the address of the proxy to the :class:`HTTPSConnection`
constructor, and the address of the host that we eventually want to reach to
the :meth:`~HTTPConnection.set_tunnel` method::
>>> import http.client
>>> conn = http.client.HTTPSConnection("localhost", 8080)
>>> conn.set_tunnel("www.python.org")
>>> conn.request("HEAD","/index.html")
.. 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(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.
.. 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.readinto(b)
Reads up to the next len(b) bytes of the response body into the buffer *b*.
Returns the number of bytes read.
.. versionadded:: 3.3
.. 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.
.. attribute:: HTTPResponse.closed
Is ``True`` if the stream is closed.
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() # This will return entire content.
>>> # The following example demonstrates reading data in chunks.
>>> conn.request("GET", "/index.html")
>>> r1 = conn.getresponse()
>>> while not r1.closed:
... print(r1.read(200)) # 200 bytes
b'<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"...
...
>>> # Example of an invalid request
>>> 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({'@number': 12524, '@type': 'issue', '@action': 'show'})
>>> headers = {"Content-type": "application/x-www-form-urlencoded",
... "Accept": "text/plain"}
>>> conn = http.client.HTTPConnection("bugs.python.org")
>>> conn.request("POST", "", params, headers)
>>> response = conn.getresponse()
>>> print(response.status, response.reason)
302 Found
>>> data = response.read()
>>> data
b'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. It should be noted that custom HTTP methods
+are also handled in :class:`urllib.request.Request` by sending the appropriate
+method attribute.Here is an example session that shows how to do ``PUT``
request using http.client::
>>> # This creates an HTTP message
>>> # with the content of BODY as the enclosed representation
>>> # for the resource http://localhost:8080/file
...
>>> import http.client
>>> BODY = "***filecontents***"
>>> conn = http.client.HTTPConnection("localhost", 8080)
>>> conn.request("PUT", "/file", BODY)
>>> response = conn.getresponse()
>>> print(response.status, response.reason)
200, OK
.. _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.
