import turtle
def koch(size, n):
if n == 0:
turtle.fd(size)
else:
for angle in [0, 60, -120, 60]:
turtle.left(angle)
koch(size/3, n-1)
def main():
turtle.setup(800, 400)
turtle.penup()
turtle.goto(-300, -50)
turtle.pendown()
turtle.pensize(2)
koch(600, 3)
turtle.hideturtle()
turtle.done()
if __name__ == '__main__':
main()
运行结果: