代码如下：

import turtledef main():    t = turtle.Turtle()    t.hideturtle()    t.speed(10)    level = 12    fract(t,-80,60,80,60,level)def fract(t,x1,y1,x2,y2,level):    newX = 0    newY = 0    if level == 0:        drawLine(t,x1,y1,x2,y2)    else:        newX = (x1+x2)/2 + (y2-y1)/2        newY = (y1+y2)/2 - (x2-x1)/2        fract(t,x1,y1,newX,newY,level-1)        fract(t,newX,newY,x2,y2,level-1)def drawLine(t,x1,y1,x2,y2):    t.up()    t.goto(x1,y1)    t.down()    t.goto(x2,y2)main()

效果如图：