| \section{Built-in module \sectcode{httplib}} |
| \stmodindex{httplib} |
| \index{HTTP} |
| |
| \renewcommand{\indexsubitem}{(in module httplib)} |
| |
| This module defines a class which implements the client side of the |
| HTTP protocol. It is normally not used directly --- the module |
| \code{urllib} uses it to handle URLs that use HTTP. |
| \stmodindex{urllib} |
| |
| The module defines one class, \code{HTTP}. An \code{HTTP} 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{host:port}, else the default HTTP port (80) is used. |
| If no host is passed, no connection is made, and the \code{connect} |
| method should be used to connect to a server. |
| |
| Once an \code{HTTP} instance has been connected to an HTTP server, it |
| should be used as follows: |
| |
| \begin{enumerate} |
| |
| \item[1.] Make exactly one call to the \code{putrequest()} method. |
| |
| \item[2.] Make zero or more calls to the \code{putheader()} method. |
| |
| \item[3.] Call the \code{endheaders()} method (this can be omitted if |
| step 4. makes no calls). |
| |
| \item[4.] Optional calls to the \code{send()} method. |
| |
| \item[5.] Call the \code{getreply()} method. |
| |
| \item[6.] Call the \code{getfile()} method and read the data off the |
| file object that it returns. |
| |
| \end{enumerate} |
| |
| \code{HTTP} instances have the following methods: |
| |
| \begin{funcdesc}{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{funcdesc} |
| |
| \begin{funcdesc}{connect}{host\optional{\, port}} |
| Connect to the server given by \var{host} and \var{port}. See the |
| intro for the default port. This should be called directly only if |
| the instance was instantiated without passing a host. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{send}{data} |
| Send data to the server. This should be used directly only after the |
| \code{endheaders()} method has been called and before |
| \code{getreply()} has been called. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{putrequest}{request\, selector} |
| 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/1.0}). |
| \end{funcdesc} |
| |
| \begin{funcdesc}{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{funcdesc} |
| |
| \begin{funcdesc}{endheaders}{} |
| Send a blank line to the server, signalling the end of the headers. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{getreply}{} |
| Complete the request by shutting down the sending end of the socket, |
| read the reply from the server, and return a triple (\var{replycode}, |
| \var{message}, \var{headers}). Here \var{replycode} is the integer |
| reply code from the request (e.g.\ \code{200} if the request was |
| handled properly); \var{message} is the message string corresponding |
| to the reply code; and \var{header} is an instance of the class |
| \code{rfc822.Message} containing the headers received from the server. |
| See the description of the \code{rfc822} module. |
| \stmodindex{rfc822} |
| \end{funcdesc} |
| |
| \begin{funcdesc}{getfile}{} |
| Return a file object from which the data returned by the server can be |
| read, using the \code{read()}, \code{readline()} or \code{readlines()} |
| methods. |
| \end{funcdesc} |