Python学习Turtle库画对称勾股树体会分形惊艳

import turtle 
def bintree(size):
    angle = 60    # 分叉的角度
    if size > 5:    # 长度退出条件
        turtle.forward(size)
        turtle.left(angle)
        bintree(size / 1.6)
        turtle.right(angle*2)
        bintree(size / 1.6)
        turtle.left(angle)
        turtle.backward(size)
def main():
    turtle.speed(0)
    turtle.hideturtle()
    turtle.penup()
    turtle.left(90)
    turtle.backward(100)
    turtle.showturtle()
    turtle.pendown()
    turtle.pensize(2)
    turtle.color('green')
    bintree(150)
    turtle.done() 
if __name__ == '__main__':
 
    main()

from turtle import *
 def Square(self,length):
    for _ in range(5):
        self.forward(length)
        self.right(90)
def Triangle(self,length):
    self.left(45)
    self.forward(length/2**0.5)
    self.right(90)
    self.forward(length/2**0.5)
    self.right(135)
    self.forward(length)
def Move2Right(self,length):
    self.back(length)
    self.right(45)
    self.forward(length/2**0.5)
    self.right(90) 
def Recursive(n, tracer, length):
    if n<1: return
    tracers = []
    for left in tracer:
        if n<3: left.pencolor('green')
        else: left.pencolor('brown')
        Square(left, length)
        Triangle(left, length)
        right = left.clone()
        left.right(45)
        Move2Right(right, length)
        tracers.append(left)
        tracers.append(right)
    Recursive(n-1, tracers, length/2**0.5)
def Setup(self, length, speed):
    self.hideturtle()
    self.speed(speed)
    self.penup()
    self.goto(-length*0.5, -length*1.8)
    self.seth(90)
    self.pensize(2)
    self.pendown() 
def main(level, length, speed=-1):
    setup(800,600)
    title('Fractal Tree')
    if speed==-1: tracer(0)
    else: tracer(1)
    t = Turtle()
    Setup(t, length, speed)
    from time import sleep
    sleep(2)
    Recursive(level, list([t]), length)
    done()
    bye() 
if __name__ == '__main__':    
    main(6,150,10)