python 谢尔宾斯基三角形的递归实现

import turtle


def draw(points):
    # 根据三个坐标，画一个三角形
    t.penup()
    t.goto(points['left'])
    t.pendown()
    t.goto(points['top'])
    t.goto(points['right'])
    t.goto(points['left'])
    

def getMid(p1,p2):
    # 获取两个坐标的中点的坐标
    return (p1[0]+p2[0])/2,(p1[1]+p2[1])/2
    
    
def sierpinski(degree,points):
    draw(points)
    if degree > 0:
        # 以原三角形左边底角坐标为起点，画一个边长为原来三角形边长一半的等边三角形
        sierpinski(degree-1,{'left':points['left'],'top':getMid(points['left'],points['top']),'right':getMid(points['left'],points['right']) })
        
        # 以原三角形左边中点坐标为起点，画一个边长为原来三角形边长一半的等边三角形
        sierpinski(degree-1,{'left':getMid(points['left'],points['top']),'top':points['top'],'right':getMid(points['top'],points['right'])  })
        
        # 以原三角形底边中点坐标为起点，画一个边长为原来三角形边长一半的等边三角形
        sierpinski(degree-1,{'left':getMid(points['left'],points['right']),'top':getMid(points['top'],points['right']),'right':points['right'] })

        
if __name__ == "__main__":
    t = turtle.Turtle()
    t.speed(3)  # 画笔速度
    # 初始的三角形的三个顶点
    points = {'left':(-200,-100),'top':(0,200),'right':(200,-100)}
    sierpinski(3,points)

    turtle.done()