import turtle  
import math 

def fractal(aturt, depth, maxdepth):  
   if depth > maxdepth:  
     return  
   length = 180*((math.sqrt(2)/2)**depth)  
   anotherturt = aturt.clone()  
   aturt.forward(length)  
   aturt.left(45)  
   fractal(aturt, depth+1, maxdepth)  
   anotherturt.right(90)  
   anotherturt.forward(length)  
   anotherturt.left(90)  
   anotherturt.forward(length)  
   if depth != maxdepth:  
     turt3 = anotherturt.clone()  
     turt3.left(45)  
     turt3.forward(180*((math.sqrt(2)/2)**(1+depth)))  
     turt3.right(90)  
     fractal(turt3, depth+1, maxdepth)  
   anotherturt.left(90)  
   anotherturt.forward(length)  

def draw_fractal():  
   window = turtle.Screen()  
   turt = turtle.Turtle()  
   turt.hideturtle()  
   turt.penup()  
   turt.goto(-75, -225)  
   turt.pendown()  
   turt.speed(0)  
   turt.left(90)  
   #change the second argument to get a bigger tree!
   fractal(turt, 1, 2)  
   window.exitonclick()  

draw_fractal()