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 (
 "" %
 (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")