url requesting with different proxies in python

I am trying to retriv开发者_如何学Goe some pages which are google search results and cached. Actually i have two problems for now. I can normally download the first ten results, but cant get it to work to go to "next" 10 pages. I have tried to use regular expressions to find the next control in the page and go from there, i couldn't get it to work. But my other problem, which is much more important, is that my ip address is blocked by google that i can no longer view the cached results. So one solution coming to my mind is to use a proxy for making the url requests, and renewing this proxy in some intervals. But i do not have an idea of how to make this job. I tried to search the web for solutions, but i could not come up with a good one. I would be very happy if you can give me some advice.

5th example? Or maybe 3rd example?