1 2 3 4 5 6 7 8 9
def generate_x(): i = 0 while i < 10: print i yield i i += 1 for x in generate_x(): print x
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
0 0 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9