本代码演示了python的urllib2模块如何使用代理，以及需要登录验证的proxy

# The proxy address and port:  proxy_info = { 'host' : 'proxy.myisp.com',                 'port' : 3128               }     # We create a handler for the proxy  proxy_support = urllib2.ProxyHandler({"http" : "http://%(host)s:%(port)d" % proxy_info})     # We create an opener which uses this handler:  opener = urllib2.build_opener(proxy_support)     # Then we install this opener as the default opener for urllib2:  urllib2.install_opener(opener)     # Now we can send our HTTP request:  htmlpage = urllib2.urlopen("http://sebsauvage.net/").read(200000)     #如果代理需要验证  proxy_info = { 'host' : 'proxy.myisp.com',                 'port' : 3128,                 'user' : 'John Doe',                 'pass' : 'mysecret007'               }  proxy_support = urllib2.ProxyHandler({"http" : "http://%(user)s:%(pass)s@%(host)s:%(port)d" % proxy_info})  opener = urllib2.build_opener(proxy_support)  urllib2.install_opener(opener)  htmlpage = urllib2.urlopen("http://sebsauvage.net/").read(200000)