7.12 The httplib Module

The httplib module, shown in Example 7-26, provides an HTTP client interface.

Example 7-26. Using the httplib Module

File: httplib-example-1.py

import httplib

USER_AGENT = "httplib-example-1.py"

class Error:
    # indicates an HTTP error
    def _ _init_ _(self, url, errcode, errmsg, headers):
        self.url = url
        self.errcode = errcode
        self.errmsg = errmsg
        self.headers = headers
    def _ _repr_ _(self):
        return (
            "<Error for %s: %s %s>" %
            (self.url, self.errcode, self.errmsg)
            )

class Server:

    def _ _init_ _(self, host):
        self.host = host

    def fetch(self, path):
        http = httplib.HTTP(self.host)

        # write header
        http.putrequest("GET", path)
        http.putheader("User-Agent", USER_AGENT)
        http.putheader("Host", self.host)
        http.putheader("Accept", "*/*")
        http.endheaders()

        # get response
        errcode, errmsg, headers = http.getreply()

        if errcode != 200:
            raise Error(errcode, errmsg, headers)

        file = http.getfile()
        return file.read()

if _ _name_ _ == "_ _main_ _":

    server = Server("www.pythonware.com")
    print server.fetch("/index.htm")

Note that the HTTP client provided httplib blocks while waiting for the server to respond. For an asynchronous solution, which among other things allows you to issue multiple requests in parallel, see the examples for the asyncore module.

7.12.1 Posting Data to an HTTP Server

The httplib module also allows you to send other HTTP commands, such as POST, as shown in Example 7-27.

Example 7-27. Using the httplib Module to Post Data

File: httplib-example-2.py

import httplib

USER_AGENT = "httplib-example-2.py"

def post(host, path, data, type=None):

    http = httplib.HTTP(host)

    # write header
    http.putrequest("PUT", path)
    http.putheader("User-Agent", USER_AGENT)
    http.putheader("Host", host)
    if type:
        http.putheader("Content-Type", type)
    http.putheader("Content-Length", str(len(size)))
    http.endheaders()

    # write body
    http.send(data)

    # get response
    errcode, errmsg, headers = http.getreply()

    if errcode != 200:
        raise Error(errcode, errmsg, headers)

    file = http.getfile()
    return file.read()

if _ _name_ _ == "_ _main_ _":

    post("www.spam.egg", "/bacon.htm", "a piece of data", "text/plain")