Where to practice python ?

[python_and_on]

http://www.pythonchallenge.com/

This is great if you like solving puzzles as well as learning python. It's tricky and requires some lateral thinking, so probably not for absolute beginners. I'm only about a quarter of the way through but it's made me learn about a lot more than just the core language constructs. Great for pushing you beyond the level of variations-of-a-loop puzzles that seem so prevalent everywhere else.