1#!/usr/bin/env python 2""" turtle-example-suite: 3 4 tdemo_minimal_hanoi.py 5 6A minimal 'Towers of Hanoi' animation: 7A tower of 6 discs is transferred from the 8left to the right peg. 9 10An imho quite elegant and concise 11implementation using a tower class, which 12is derived from the built-in type list. 13 14Discs are turtles with shape "square", but 15stretched to rectangles by shapesize() 16 --------------------------------------- 17 To exit press STOP button 18 --------------------------------------- 19""" 20from turtle import * 21 22class Disc(Turtle): 23 def __init__(self, n): 24 Turtle.__init__(self, shape="square", visible=False) 25 self.pu() 26 self.shapesize(1.5, n*1.5, 2) # square-->rectangle 27 self.fillcolor(n/6., 0, 1-n/6.) 28 self.st() 29 30class Tower(list): 31 "Hanoi tower, a subclass of built-in type list" 32 def __init__(self, x): 33 "create an empty tower. x is x-position of peg" 34 self.x = x 35 def push(self, d): 36 d.setx(self.x) 37 d.sety(-150+34*len(self)) 38 self.append(d) 39 def pop(self): 40 d = list.pop(self) 41 d.sety(150) 42 return d 43 44def hanoi(n, from_, with_, to_): 45 if n > 0: 46 hanoi(n-1, from_, to_, with_) 47 to_.push(from_.pop()) 48 hanoi(n-1, with_, from_, to_) 49 50def play(): 51 onkey(None,"space") 52 clear() 53 try: 54 hanoi(6, t1, t2, t3) 55 write("press STOP button to exit", 56 align="center", font=("Courier", 16, "bold")) 57 except Terminator: 58 pass # turtledemo user pressed STOP 59 60def main(): 61 global t1, t2, t3 62 ht(); penup(); goto(0, -225) # writer turtle 63 t1 = Tower(-250) 64 t2 = Tower(0) 65 t3 = Tower(250) 66 # make tower of 6 discs 67 for i in range(6,0,-1): 68 t1.push(Disc(i)) 69 # prepare spartanic user interface ;-) 70 write("press spacebar to start game", 71 align="center", font=("Courier", 16, "bold")) 72 onkey(play, "space") 73 listen() 74 return "EVENTLOOP" 75 76if __name__=="__main__": 77 msg = main() 78 print msg 79 mainloop() 80