This is the website that I used to learn python. What's so great about this website is that it takes you through the key parts of python, and shows you how to integrate them. You can test your own knowledge with some mini-tests included in the tutorial which involve looking at code, and deciding how effective it is. It also allows you to run python client-side in your browser, giving you exercises to make programs. Also, when you make a mistake, it doesn't give a nonsense error message. It tells you what is likely to be wrong.
In conclusion, the site will improve your overall understanding on reading and writing python.