How to learn python from scratch?

[Sly]

This is where I learned. Probably one of the best resources out there (can't go wrong with MIT). And free, of course. It will require quite a bit of dedication and self-discipline (if you're new to self-studying), but it is a complete course.

ps: You mentioned that "Codeacademy is not good for applying knowledge" and stuff, but don't pay attention to it. All that matters is that you're consistently getting practice.

pps: Project Euler if you want to practice some tough math-infused problems.