I\'ve been arguing with some friends on the university, and we can\'t get to a point to which is the framework with more scalability for web applications (and still very fast).<
Several good points already. My main point would be this: A person who knows python inside and out will probably be able to make more scalable code using python than using Java. And there are many massively big sites that use all the technologies that you mention, so I don't think there's really any big advantage either way.
For the most part, you should stick to what you're familiar with unless there's a really significant reason to go another way.