@shai_loantz good catch, I had a pair of brackets missing. edited my comment :)

given that s = "awesome" the function triangle() can be written as a simple expression: [[s[:i+ 1 ]] for i in range(len(s))] without the useless list allocation at the beginning, the problem mentioned in the post is eliminated

Although languages don't have performance, implementations do. For example nuitka is considerably faster than CPython. And Python 2.x is faster than Python 3.x.

Rubik's cube!

"how to get started?" - you normally start to use a piece of software and if it's open-source and you find a bug to fix or space to improve the code, you do it.

At first you should figure out what do you want to create, make plans and set requirements. Planning comes first and implementation follows. Tools (and the selection of tools) only matter in the light of a problem: if there's no problem to solve, why would you need any tool anyway? Also I'm not sure about what you mean by "beautiful". Visual design and aesthetics is an entirely different field. To learn about that visit an art school. :) On the choice between PHP vs. Node - I'd recommend learning Node. A good grasp of JavaScript is a more versatile skill to acquire since you will use the same language to write the client-side code too. In fact, making a web app isomorphic is a very interesting way to provide great user experience! Here's a good article on the topic: What is an isomorphic application?

"You have the markup, css and js seperated into this one compontent you are building." - well, except for maybe the CSS part, this is pretty much what React is. I see React as being one possible implementation (or at least kinda similar) of Web Components before they become a wide-spread standard and get browser support. Am I missing something?