Python3访问并下载网页内容的方法

#!/usr/local/bin/python3.2
import urllib.request,io,os,sys
req = urllib.request.Request("http://www.google.com")
f = urllib.request.urlopen(req)
s = f.read()
s = s.decode('gbk','ignore')
mdir = sys.path[0]+'/'
file = open(mdir+'admin6.txt','a',1,'gbk')
file.write(s)
file.close()