turtle x y step ratio fn_2 fn_1 fn x0 y0 step_x step_y screen turtle ratio = 5 x0 = 0 y0 = 0 fn_2 = 0 fn_1 = 1 i 7 fn = 10 + True fn_2 True fn_1 step = 10 * True fn True ratio step_x = 0 step step_y = 0 step True or True == i % i 4 1 True == i % i 4 2 step_x = 0 - 0 True step True or True == i % i 4 2 True == i % i 4 3 step_y = 0 - 0 True step j 4 x = 0 + True x0 True step_x y = 0 + True y0 True step_y j == 3 turtle down turtle x0, y0 turtle 255, 0, 0 turtle step, 90 turtle 0, 0, 0 turtle up turtle x, y fn_2 = 10 fn_1 fn_1 = 10 fn x0 = 10 x y0 = 10 y []