It was hard to me. I could not understand Algorithm what to solve Fibonacci sequence and could not to reading English because I am Japanese. Especially, this sequence "even-valued terms". What mean it in Japanese? I had asked teacher(google) to tell me about it. Then it was found, Explanation site of Project Euler in Japanese. We are not good about English It is regrettable.
# -*- coding: utf-8 -*- def num(x): if x == 0 or x == 1: return 1 else: return num(x-1) + num(x-2) if __name__ == '__main__': d = 1 num_list = [0] while 1: h = num(d) if h % 2 == 0: num_list.append(h) if h>=4000000: break d = d+1 print sum(num_list)