: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 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=None[, 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. 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 typle 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. .. class:: HTTPSConnection(host, port=None, key_file=None, cert_file=None, strict=None[, 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). .. class:: HTTPResponse(sock, debuglevel=0, strict=0, method=None, url=None) Class whose instances are returned upon successful connection. Not instantiated directly by user. 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 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`SWITCHING_PROTOCOLS` | ``101`` | HTTP/1.1, `RFC 2616, Section | | | | 10.1.2 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`PROCESSING` | ``102`` | WEBDAV, `RFC 2518, Section 10.1 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`OK` | ``200`` | HTTP/1.1, `RFC 2616, Section | | | | 10.2.1 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`CREATED` | ``201`` | HTTP/1.1, `RFC 2616, Section | | | | 10.2.2 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`ACCEPTED` | ``202`` | HTTP/1.1, `RFC 2616, Section | | | | 10.2.3 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`NON_AUTHORITATIVE_INFORMATION` | ``203`` | HTTP/1.1, `RFC 2616, Section | | | | 10.2.4 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`NO_CONTENT` | ``204`` | HTTP/1.1, `RFC 2616, Section | | | | 10.2.5 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`RESET_CONTENT` | ``205`` | HTTP/1.1, `RFC 2616, Section | | | | 10.2.6 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`PARTIAL_CONTENT` | ``206`` | HTTP/1.1, `RFC 2616, Section | | | | 10.2.7 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`MULTI_STATUS` | ``207`` | WEBDAV `RFC 2518, Section 10.2 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :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 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`MOVED_PERMANENTLY` | ``301`` | HTTP/1.1, `RFC 2616, Section | | | | 10.3.2 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`FOUND` | ``302`` | HTTP/1.1, `RFC 2616, Section | | | | 10.3.3 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`SEE_OTHER` | ``303`` | HTTP/1.1, `RFC 2616, Section | | | | 10.3.4 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`NOT_MODIFIED` | ``304`` | HTTP/1.1, `RFC 2616, Section | | | | 10.3.5 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`USE_PROXY` | ``305`` | HTTP/1.1, `RFC 2616, Section | | | | 10.3.6 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`TEMPORARY_REDIRECT` | ``307`` | HTTP/1.1, `RFC 2616, Section | | | | 10.3.8 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`BAD_REQUEST` | ``400`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.1 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`UNAUTHORIZED` | ``401`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.2 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`PAYMENT_REQUIRED` | ``402`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.3 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`FORBIDDEN` | ``403`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.4 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`NOT_FOUND` | ``404`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.5 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`METHOD_NOT_ALLOWED` | ``405`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.6 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`NOT_ACCEPTABLE` | ``406`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.7 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`PROXY_AUTHENTICATION_REQUIRED` | ``407`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.8 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`REQUEST_TIMEOUT` | ``408`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.9 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`CONFLICT` | ``409`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.10 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`GONE` | ``410`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.11 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`LENGTH_REQUIRED` | ``411`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.12 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`PRECONDITION_FAILED` | ``412`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.13 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`REQUEST_ENTITY_TOO_LARGE` | ``413`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.14 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`REQUEST_URI_TOO_LONG` | ``414`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.15 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`UNSUPPORTED_MEDIA_TYPE` | ``415`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.16 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`REQUESTED_RANGE_NOT_SATISFIABLE` | ``416`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.17 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`EXPECTATION_FAILED` | ``417`` | HTTP/1.1, `RFC 2616, Section | | | | 10.4.18 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`UNPROCESSABLE_ENTITY` | ``422`` | WEBDAV, `RFC 2518, Section 10.3 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`LOCKED` | ``423`` | WEBDAV `RFC 2518, Section 10.4 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`FAILED_DEPENDENCY` | ``424`` | WEBDAV, `RFC 2518, Section 10.5 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :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 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`NOT_IMPLEMENTED` | ``501`` | HTTP/1.1, `RFC 2616, Section | | | | 10.5.2 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`BAD_GATEWAY` | ``502`` | HTTP/1.1 `RFC 2616, Section | | | | 10.5.3 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`SERVICE_UNAVAILABLE` | ``503`` | HTTP/1.1, `RFC 2616, Section | | | | 10.5.4 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`GATEWAY_TIMEOUT` | ``504`` | HTTP/1.1 `RFC 2616, Section | | | | 10.5.5 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`HTTP_VERSION_NOT_SUPPORTED` | ``505`` | HTTP/1.1, `RFC 2616, Section | | | | 10.5.6 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :const:`INSUFFICIENT_STORAGE` | ``507`` | WEBDAV, `RFC 2518, Section 10.6 | | | | `_ | +------------------------------------------+---------+-----------------------------------------------------------------------+ | :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 *headers* argument should be a mapping of extra HTTP headers to send with the request. .. 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.