ref: a8d00e5d56b261376410c3c87c46327362763bd8
dir: /sys/src/cmd/python/Doc/lib/libhttplib.tex/
\section{\module{httplib} --- HTTP protocol client} \declaremodule{standard}{httplib} \modulesynopsis{HTTP and HTTPS protocol client (requires sockets).} \indexii{HTTP}{protocol} \index{HTTP!\module{httplib} (standard module)} This module defines classes which implement the client side of the HTTP and HTTPS protocols. It is normally not used directly --- the module \refmodule{urllib}\refstmodindex{urllib} uses it to handle URLs that use HTTP and HTTPS. \begin{notice} HTTPS support is only available if the \refmodule{socket} module was compiled with SSL support. \end{notice} \begin{notice} The public interface for this module changed substantially in Python 2.0. The \class{HTTP} class is retained only for backward compatibility with 1.5.2. It should not be used in new code. Refer to the online docstrings for usage. \end{notice} The module provides the following classes: \begin{classdesc}{HTTPConnection}{host\optional{, port}} 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 \code{\var{host}:\var{port}}, else the default HTTP port (80) is used. For example, the following calls all create instances that connect to the server at the same host and port: \begin{verbatim} >>> h1 = httplib.HTTPConnection('www.cwi.nl') >>> h2 = httplib.HTTPConnection('www.cwi.nl:80') >>> h3 = httplib.HTTPConnection('www.cwi.nl', 80) \end{verbatim} \versionadded{2.0} \end{classdesc} \begin{classdesc}{HTTPSConnection}{host\optional{, port, key_file, cert_file}} A subclass of \class{HTTPConnection} that uses SSL for communication with secure servers. Default port is \code{443}. \var{key_file} is the name of a PEM formatted file that contains your private key. \var{cert_file} is a PEM formatted certificate chain file. \warning{This does not do any certificate verification!} \versionadded{2.0} \end{classdesc} \begin{classdesc}{HTTPResponse}{sock\optional{, debuglevel=0}\optional{, strict=0}} Class whose instances are returned upon successful connection. Not instantiated directly by user. \versionadded{2.0} \end{classdesc} The following exceptions are raised as appropriate: \begin{excdesc}{HTTPException} The base class of the other exceptions in this module. It is a subclass of \exception{Exception}. \versionadded{2.0} \end{excdesc} \begin{excdesc}{NotConnected} A subclass of \exception{HTTPException}. \versionadded{2.0} \end{excdesc} \begin{excdesc}{InvalidURL} A subclass of \exception{HTTPException}, raised if a port is given and is either non-numeric or empty. \versionadded{2.3} \end{excdesc} \begin{excdesc}{UnknownProtocol} A subclass of \exception{HTTPException}. \versionadded{2.0} \end{excdesc} \begin{excdesc}{UnknownTransferEncoding} A subclass of \exception{HTTPException}. \versionadded{2.0} \end{excdesc} \begin{excdesc}{UnimplementedFileMode} A subclass of \exception{HTTPException}. \versionadded{2.0} \end{excdesc} \begin{excdesc}{IncompleteRead} A subclass of \exception{HTTPException}. \versionadded{2.0} \end{excdesc} \begin{excdesc}{ImproperConnectionState} A subclass of \exception{HTTPException}. \versionadded{2.0} \end{excdesc} \begin{excdesc}{CannotSendRequest} A subclass of \exception{ImproperConnectionState}. \versionadded{2.0} \end{excdesc} \begin{excdesc}{CannotSendHeader} A subclass of \exception{ImproperConnectionState}. \versionadded{2.0} \end{excdesc} \begin{excdesc}{ResponseNotReady} A subclass of \exception{ImproperConnectionState}. \versionadded{2.0} \end{excdesc} \begin{excdesc}{BadStatusLine} A subclass of \exception{HTTPException}. Raised if a server responds with a HTTP status code that we don't understand. \versionadded{2.0} \end{excdesc} The constants defined in this module are: \begin{datadesc}{HTTP_PORT} The default port for the HTTP protocol (always \code{80}). \end{datadesc} \begin{datadesc}{HTTPS_PORT} The default port for the HTTPS protocol (always \code{443}). \end{datadesc} and also the following constants for integer status codes: \begin{tableiii}{l|c|l}{constant}{Constant}{Value}{Definition} \lineiii{CONTINUE}{\code{100}} {HTTP/1.1, \ulink{RFC 2616, Section 10.1.1} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.1.1}} \lineiii{SWITCHING_PROTOCOLS}{\code{101}} {HTTP/1.1, \ulink{RFC 2616, Section 10.1.2} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.1.2}} \lineiii{PROCESSING}{\code{102}} {WEBDAV, \ulink{RFC 2518, Section 10.1} {http://www.webdav.org/specs/rfc2518.html#STATUS_102}} \lineiii{OK}{\code{200}} {HTTP/1.1, \ulink{RFC 2616, Section 10.2.1} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.1}} \lineiii{CREATED}{\code{201}} {HTTP/1.1, \ulink{RFC 2616, Section 10.2.2} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.2}} \lineiii{ACCEPTED}{\code{202}} {HTTP/1.1, \ulink{RFC 2616, Section 10.2.3} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.3}} \lineiii{NON_AUTHORITATIVE_INFORMATION}{\code{203}} {HTTP/1.1, \ulink{RFC 2616, Section 10.2.4} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.4}} \lineiii{NO_CONTENT}{\code{204}} {HTTP/1.1, \ulink{RFC 2616, Section 10.2.5} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.5}} \lineiii{RESET_CONTENT}{\code{205}} {HTTP/1.1, \ulink{RFC 2616, Section 10.2.6} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.6}} \lineiii{PARTIAL_CONTENT}{\code{206}} {HTTP/1.1, \ulink{RFC 2616, Section 10.2.7} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.7}} \lineiii{MULTI_STATUS}{\code{207}} {WEBDAV \ulink{RFC 2518, Section 10.2} {http://www.webdav.org/specs/rfc2518.html#STATUS_207}} \lineiii{IM_USED}{\code{226}} {Delta encoding in HTTP, \rfc{3229}, Section 10.4.1} \lineiii{MULTIPLE_CHOICES}{\code{300}} {HTTP/1.1, \ulink{RFC 2616, Section 10.3.1} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.1}} \lineiii{MOVED_PERMANENTLY}{\code{301}} {HTTP/1.1, \ulink{RFC 2616, Section 10.3.2} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.2}} \lineiii{FOUND}{\code{302}} {HTTP/1.1, \ulink{RFC 2616, Section 10.3.3} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.3}} \lineiii{SEE_OTHER}{\code{303}} {HTTP/1.1, \ulink{RFC 2616, Section 10.3.4} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.4}} \lineiii{NOT_MODIFIED}{\code{304}} {HTTP/1.1, \ulink{RFC 2616, Section 10.3.5} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.5}} \lineiii{USE_PROXY}{\code{305}} {HTTP/1.1, \ulink{RFC 2616, Section 10.3.6} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.6}} \lineiii{TEMPORARY_REDIRECT}{\code{307}} {HTTP/1.1, \ulink{RFC 2616, Section 10.3.8} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.8}} \lineiii{BAD_REQUEST}{\code{400}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.1} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.1}} \lineiii{UNAUTHORIZED}{\code{401}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.2} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.2}} \lineiii{PAYMENT_REQUIRED}{\code{402}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.3} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.3}} \lineiii{FORBIDDEN}{\code{403}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.4} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.4}} \lineiii{NOT_FOUND}{\code{404}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.5} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.5}} \lineiii{METHOD_NOT_ALLOWED}{\code{405}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.6} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.6}} \lineiii{NOT_ACCEPTABLE}{\code{406}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.7} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.7}} \lineiii{PROXY_AUTHENTICATION_REQUIRED} {\code{407}}{HTTP/1.1, \ulink{RFC 2616, Section 10.4.8} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.8}} \lineiii{REQUEST_TIMEOUT}{\code{408}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.9} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.9}} \lineiii{CONFLICT}{\code{409}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.10} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.10}} \lineiii{GONE}{\code{410}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.11} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.11}} \lineiii{LENGTH_REQUIRED}{\code{411}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.12} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.12}} \lineiii{PRECONDITION_FAILED}{\code{412}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.13} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.13}} \lineiii{REQUEST_ENTITY_TOO_LARGE} {\code{413}}{HTTP/1.1, \ulink{RFC 2616, Section 10.4.14} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.14}} \lineiii{REQUEST_URI_TOO_LONG}{\code{414}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.15} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.15}} \lineiii{UNSUPPORTED_MEDIA_TYPE}{\code{415}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.16} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.16}} \lineiii{REQUESTED_RANGE_NOT_SATISFIABLE}{\code{416}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.17} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.17}} \lineiii{EXPECTATION_FAILED}{\code{417}} {HTTP/1.1, \ulink{RFC 2616, Section 10.4.18} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.18}} \lineiii{UNPROCESSABLE_ENTITY}{\code{422}} {WEBDAV, \ulink{RFC 2518, Section 10.3} {http://www.webdav.org/specs/rfc2518.html#STATUS_422}} \lineiii{LOCKED}{\code{423}} {WEBDAV \ulink{RFC 2518, Section 10.4} {http://www.webdav.org/specs/rfc2518.html#STATUS_423}} \lineiii{FAILED_DEPENDENCY}{\code{424}} {WEBDAV, \ulink{RFC 2518, Section 10.5} {http://www.webdav.org/specs/rfc2518.html#STATUS_424}} \lineiii{UPGRADE_REQUIRED}{\code{426}} {HTTP Upgrade to TLS, \rfc{2817}, Section 6} \lineiii{INTERNAL_SERVER_ERROR}{\code{500}} {HTTP/1.1, \ulink{RFC 2616, Section 10.5.1} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.1}} \lineiii{NOT_IMPLEMENTED}{\code{501}} {HTTP/1.1, \ulink{RFC 2616, Section 10.5.2} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.2}} \lineiii{BAD_GATEWAY}{\code{502}} {HTTP/1.1 \ulink{RFC 2616, Section 10.5.3} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.3}} \lineiii{SERVICE_UNAVAILABLE}{\code{503}} {HTTP/1.1, \ulink{RFC 2616, Section 10.5.4} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.4}} \lineiii{GATEWAY_TIMEOUT}{\code{504}} {HTTP/1.1 \ulink{RFC 2616, Section 10.5.5} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.5}} \lineiii{HTTP_VERSION_NOT_SUPPORTED}{\code{505}} {HTTP/1.1, \ulink{RFC 2616, Section 10.5.6} {http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.6}} \lineiii{INSUFFICIENT_STORAGE}{\code{507}} {WEBDAV, \ulink{RFC 2518, Section 10.6} {http://www.webdav.org/specs/rfc2518.html#STATUS_507}} \lineiii{NOT_EXTENDED}{\code{510}} {An HTTP Extension Framework, \rfc{2774}, Section 7} \end{tableiii} \begin{datadesc}{responses} This dictionary maps the HTTP 1.1 status codes to the W3C names. Example: \code{httplib.responses[httplib.NOT_FOUND]} is \code{'Not Found'}. \versionadded{2.5} \end{datadesc} \subsection{HTTPConnection Objects \label{httpconnection-objects}} \class{HTTPConnection} instances have the following methods: \begin{methoddesc}{request}{method, url\optional{, body\optional{, headers}}} This will send a request to the server using the HTTP request method \var{method} and the selector \var{url}. If the \var{body} argument is present, it should be a string of data to send after the headers are finished. The header Content-Length is automatically set to the correct value. The \var{headers} argument should be a mapping of extra HTTP headers to send with the request. \end{methoddesc} \begin{methoddesc}{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.} \end{methoddesc} \begin{methoddesc}{set_debuglevel}{level} Set the debugging level (the amount of debugging output printed). The default debug level is \code{0}, meaning no debugging output is printed. \end{methoddesc} \begin{methoddesc}{connect}{} Connect to the server specified when the object was created. \end{methoddesc} \begin{methoddesc}{close}{} Close the connection to the server. \end{methoddesc} As an alternative to using the \method{request()} method described above, you can also send your request step by step, by using the four functions below. \begin{methoddesc}{putrequest}{request, selector\optional{, skip\_host\optional{, skip_accept_encoding}}} This should be the first call after the connection to the server has been made. It sends a line to the server consisting of the \var{request} string, the \var{selector} string, and the HTTP version (\code{HTTP/1.1}). To disable automatic sending of \code{Host:} or \code{Accept-Encoding:} headers (for example to accept additional content encodings), specify \var{skip_host} or \var{skip_accept_encoding} with non-False values. \versionchanged[\var{skip_accept_encoding} argument added]{2.4} \end{methoddesc} \begin{methoddesc}{putheader}{header, argument\optional{, ...}} 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. \end{methoddesc} \begin{methoddesc}{endheaders}{} Send a blank line to the server, signalling the end of the headers. \end{methoddesc} \begin{methoddesc}{send}{data} Send data to the server. This should be used directly only after the \method{endheaders()} method has been called and before \method{getresponse()} is called. \end{methoddesc} \subsection{HTTPResponse Objects \label{httpresponse-objects}} \class{HTTPResponse} instances have the following methods and attributes: \begin{methoddesc}{read}{\optional{amt}} Reads and returns the response body, or up to the next \var{amt} bytes. \end{methoddesc} \begin{methoddesc}{getheader}{name\optional{, default}} Get the contents of the header \var{name}, or \var{default} if there is no matching header. \end{methoddesc} \begin{methoddesc}{getheaders}{} Return a list of (header, value) tuples. \versionadded{2.4} \end{methoddesc} \begin{datadesc}{msg} A \class{mimetools.Message} instance containing the response headers. \end{datadesc} \begin{datadesc}{version} HTTP protocol version used by server. 10 for HTTP/1.0, 11 for HTTP/1.1. \end{datadesc} \begin{datadesc}{status} Status code returned by server. \end{datadesc} \begin{datadesc}{reason} Reason phrase returned by server. \end{datadesc} \subsection{Examples \label{httplib-examples}} Here is an example session that uses the \samp{GET} method: \begin{verbatim} >>> import httplib >>> conn = httplib.HTTPConnection("www.python.org") >>> conn.request("GET", "/index.html") >>> r1 = conn.getresponse() >>> print r1.status, r1.reason 200 OK >>> data1 = r1.read() >>> conn.request("GET", "/parrot.spam") >>> r2 = conn.getresponse() >>> print r2.status, r2.reason 404 Not Found >>> data2 = r2.read() >>> conn.close() \end{verbatim} Here is an example session that shows how to \samp{POST} requests: \begin{verbatim} >>> import httplib, urllib >>> params = urllib.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0}) >>> headers = {"Content-type": "application/x-www-form-urlencoded", ... "Accept": "text/plain"} >>> conn = httplib.HTTPConnection("musi-cal.mojam.com:80") >>> conn.request("POST", "/cgi-bin/query", params, headers) >>> response = conn.getresponse() >>> print response.status, response.reason 200 OK >>> data = response.read() >>> conn.close() \end{verbatim}