[Python-es] obtener codigo html de una pagina de internet

[P@vel]

Este codigo me funciona para una pagina local, o que no requiera proxy. 

import urllib 
f = urllib.urlopen("http://intranet.hlg.uci.cu") 
data = f.read() 
f.close() 
print data 


Pero como yo me conecto a internet mediante un proxy trate con esto 

import urllib 
proxies = {'http': 'http://100.0.0.1:3128'} 
f = urllib.urlopen("http://www.google.com",proxies=proxies) 
data = f.read() 
f.close() 
print data 

y me da el siguiente error 
raceback (most recent call last): 
File "/home/pavel/workspace/spider/src/prueba3.py", line 6, in <module> 
f = urllib.urlopen("http://www.google.com",proxies=proxies) 
File "/usr/lib/python2.6/urllib.py", line 86, in urlopen 
return opener.open(url) 
File "/usr/lib/python2.6/urllib.py", line 205, in open 
return getattr(self, name)(url) 
File "/usr/lib/python2.6/urllib.py", line 360, in open_http 
return self.http_error(url, fp, errcode, errmsg, headers) 
File "/usr/lib/python2.6/urllib.py", line 373, in http_error 
result = method(url, fp, errcode, errmsg, headers) 
File "/usr/lib/python2.6/urllib.py", line 703, in http_error_407 
errcode, errmsg, headers) 
File "/usr/lib/python2.6/urllib.py", line 383, in http_error_default 
raise IOError, ('http error', errcode, errmsg, headers) 
IOError: ('http error', 407, 'Proxy Authentication Required', <httplib.HTTPMessage instance at 0x93f4e6c>) 

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