sierpinski.py

import turtle

def drawTriangle(points,color,myTurtle):
  myTurtle.fillcolor(color)
  myTurtle.up()
  myTurtle.goto(points[0][0],points[0][1])
  myTurtle.down()
  myTurtle.begin_fill()
  myTurtle.goto(points[1][0],points[1][1])
  myTurtle.goto(points[2][0],points[2][1])
  myTurtle.goto(points[0][0],points[0][1])
  myTurtle.end_fill()

def getMid(p1,p2):
  return ( (p1[0]+p2[0]) / 2, (p1[1] + p2[1]) / 2)

def sierpinski(points,degree,myTurtle):
  colormap = ['blue','red','green','white','yellow',
  'violet','orange']
  drawTriangle(points,colormap[degree],myTurtle)
  if degree > 0:
    sierpinski([points[0], getMid(points[0], points[1]), getMid(points[0], points[2])], degree-1, myTurtle)
    sierpinski([points[1], getMid(points[0], points[1]), getMid(points[1], points[2])], degree-1, myTurtle)
    sierpinski([points[2], getMid(points[2], points[1]), getMid(points[0], points[2])], degree-1, myTurtle)

myTurtle = turtle.Turtle()
myWin = turtle.Screen()
myPoints = [[-100,-50],[0,100],[100,-50]]
sierpinski(myPoints,3,myTurtle)