解决python3 urllib中urlopen报错的问题

a new urllib package was created. It consists of code from 
urllib, urllib2, urlparse, and robotparser. The old 
modules have all been removed. The new package has five submodules: 
urllib.parse, urllib.request, urllib.response, 
urllib.error, and urllib.robotparser. The 
urllib.request.urlopen() function uses the url opener from 
urllib2. (Note that the unittests have not been renamed for the 
beta, but they will be renamed in the future.) 

import urllib.request 
url="http://www.baidu.com" 
get=urllib.request.urlopen(url).read() 
print(get)