【Python】koch雪花

import turtle
def koch(size,n):
    if n == 0:
        turtle.fd(size)　　　　#如果n=0画直线
    else:
        for angle in [0,60,-120,60]:　　#n>0时直线不是直线，变成了-/-这种形状
            turtle.left(angle)
            koch(size/3,n-1)　　　　#从大数字变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()