Construct a Y-Fractal tree

 

import turtle

def tree (branchLen, t) :
    if branchLen > 2 :
       t.forward (branchLen)
       t.right(20)
       tree (branchLen-15, t)
       t.left (40)
       tree (branchLen-15, t)
       t.right (20)
       t.backward (branchLen)
       
       

def main():
    t = turtle.Turtle()
    raj = turtle.Screen()
    raj.bgcolor ("black")
    t.left(90)
    t.up()
    t.backward(180)
    t.down()
    t.pensize (2)
    t.color("yellow")
    tree(115,t)
    raj.exitonclick()
    
   
main ()