As stated in the urllib2 documentation:
The urllib2 module has been split across several modules in Python 3 named urllib.request and urllib.error. The 2to3 tool will automatically adapt imports when converting your sources to Python 3.
So you should instead be saying
from urllib.request import urlopen
html = urlopen("http://www.google.com/").read()
Your current, now-edited code sample is incorrect because you are saying urllib.urlopen("http://www.google.com/") instead of just urlopen("http://www.google.com/").