Basic Robot Track using Python and OpenCV

I'm trying to build exactly the same project as in this link [login to view URL] I already built the and tested the robot. But I'm stuck on the image processing part. The FULL python code with explanation is given in Step 11 in the link (scroll down). But for some reason the code is not running on my computer. I am assuming it's different Python versions. I am using Python 2.7.14 and openCV 3.0.0. I just need you to try to run the code on your system , fix it, and send me a code thats working . It shouldn't take you long.