[Python] koch snowflake

import turtle 
def koch(size,n): 
    if n == 0: 
        turtle.fd(size) #If n=0 draw a straight line 
    else: 
        for angle in [0,60,-120,60]: #n>0 The straight line is not a straight line, it becomes -/\- this shape 
            turtle.left(angle) 
            koch(size/3,n-1) #Change from a large number to 0 
def main(): 
    turtle.setup(600,600) 
    turtle.penup () 
    turtle.goto(-200,100) 
    turtle.pendown() 
    turtle.pensize(2) 
    level = 3 
    koch(400,level) 
    turtle.right(120) 
    koch(400, level) 
    turtle.right(120) 
    koch(400 , level) 
    turtle.right(120) 
    turtle.hideturtle() 
main()