:mod:`http.client` --- HTTP protocol client
.. module:: http.client :synopsis: HTTP and HTTPS protocol client (requires sockets).
Source code: :source:`Lib/http/client.py`
.. index:: pair: HTTP; protocol single: HTTP; http.client (standard module)
.. index:: module: urllib.request
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.
.. seealso::
The `Requests package <https://requests.readthedocs.org/>`_
is recommended for a higher-level HTTP client interface.
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 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.
.. exception:: LineTooLong A subclass of :exc:`HTTPException`. Raised if an excessively long line is received in the HTTP protocol from the server.
.. exception:: RemoteDisconnected
A subclass of :exc:`ConnectionResetError` and :exc:`BadStatusLine`. Raised
by :meth:`HTTPConnection.getresponse` when the attempt to read the response
results in no data read from the connection, indicating that the remote end
has closed the connection.
.. versionadded:: 3.5
Previously, :exc:`BadStatusLine`\ ``('')`` was raised.
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``).
.. 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'``.
See :ref:`http-status-codes` for a list of HTTP status codes that are available in this module as constants.
: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 *body* is specified, the specified data is sent after the headers are
finished. It may be a string, a :term:`bytes-like object`, an open
:term:`file object`, or an iterable of :term:`bytes-like object`\s. If
*body* is a string, it is encoded as ISO-8859-1, the default for HTTP. If
it is a bytes-like object the bytes are sent as is. If it is a :term:`file
object`, the contents of the file is sent; this file object should support
at least the ``read()`` method. If the file object has a ``mode``
attribute, the data returned by the ``read()`` method will be encoded as
ISO-8859-1 unless the ``mode`` attribute contains the substring ``b``,
otherwise the data returned by ``read()`` is sent as is. If *body* is an
iterable, the elements of the iterable are sent as is until the iterable is
exhausted.
The *headers* argument should be a mapping of extra HTTP
headers to send with the request.
If *headers* does not contain a Content-Length item, one is added
automatically if possible. If *body* is ``None``, the Content-Length header
is set to ``0`` for methods that expect a body (``PUT``, ``POST``, and
``PATCH``). If *body* is a string or bytes object, the Content-Length
header is set to its length. If *body* is a :term:`file object` and it
works to call :func:`~os.fstat` on the result of its ``fileno()`` method,
then the Content-Length header is set to the ``st_size`` reported by the
``fstat`` call. Otherwise no Content-Length header is added.
.. 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.
.. versionchanged:: 3.5
If a :exc:`ConnectionError` or subclass is raised, the
:class:`HTTPConnection` object will be ready to reconnect when
a new request is sent.
.. 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. By default, this is called automatically when making a request if the client does not already have a connection.
.. 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.
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.
.. versionchanged:: 3.5 The :class:`io.BufferedIOBase` interface is now implemented and all of its reader operations are supported.
.. 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.
Here is an example session that uses the GET method:
>>> import http.client
>>> conn = http.client.HTTPSConnection("www.python.org")
>>> conn.request("GET", "/")
>>> 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", "/")
>>> r1 = conn.getresponse()
>>> while not r1.closed:
... print(r1.read(200)) # 200 bytes
b'<!doctype html>\n<!--[if"...
...
>>> # 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.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 == 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
An :class:`http.client.HTTPMessage` instance holds the headers from an HTTP response. It is implemented using the :class:`email.message.Message` class.