Part of my Python FAQ, which is doomed to never be finished. The short answer is: because it’s the actively-developed version of the language, and you should use it for the same reason you’d use 2.7 instead of 2.6. If you’re here, I’m guessing that’s not enough. You need something to sweeten the deal. Well, friend, I have got a whole mess of sugar cubes just for you. And once you’re convinced, you may enjoy the companion article, how to port to Python 3! It also has some more details on the diffences between Python 2 and 3, whereas this article doesn’t focus too much on the features removed in Python 3.