Hanoi
#!/usr/bin/env python # # [SNIPPET_NAME: Hanoi] # [SNIPPET_CATEGORIES: PyTurtle] # [SNIPPET_DESCRIPTION: Turtle plays Towers of Hanoi.] # [SNIPPET_DOCS: http://docs.python.org/library/turtle.html] # [SNIPPET_AUTHOR: Grant Bowman <[email protected]>] # [SNIPPET_LICENSE: PSF] # Code authorship from http://python.org/download/releases/2.6.4/ """ turtle-example-suite: tdemo_minimal_hanoi.py A minimal 'Towers of Hanoi' animation: A tower of 6 discs is transferred from the left to the right peg. An imho quite elegant and concise implementation using a tower class, which is derived from the built-in type list. Discs are turtles with shape "square", but stretched to rectangles by shapesize() --------------------------------------- To exit press STOP button --------------------------------------- """ from turtle import * class Disc(Turtle): def __init__(self, n): Turtle.__init__(self, shape="square", visible=False) self.pu() self.shapesize(1.5, n*1.5, 2) # square-->rectangle self.fillcolor(n/6., 0, 1-n/6.) self.st() class Tower(list): "Hanoi tower, a subclass of built-in type list" def __init__(self, x): "create an empty tower. x is x-position of peg" self.x = x def push(self, d): d.setx(self.x) d.sety(-150+34*len(self)) self.append(d) def pop(self): d = list.pop(self) d.sety(150) return d def hanoi(n, from_, with_, to_): if n > 0: hanoi(n-1, from_, to_, with_) to_.push(from_.pop()) hanoi(n-1, with_, from_, to_) def play(): onkey(None,"space") clear() hanoi(6, t1, t2, t3) write("press STOP button to exit", align="center", font=("Courier", 16, "bold")) def main(): global t1, t2, t3 ht(); penup(); goto(0, -225) # writer turtle t1 = Tower(-250) t2 = Tower(0) t3 = Tower(250) # make tower of 6 discs for i in range(6,0,-1): t1.push(Disc(i)) # prepare spartanic user interface ;-) write("press spacebar to start game", align="center", font=("Courier", 16, "bold")) onkey(play, "space") listen() return "EVENTLOOP" if __name__=="__main__": msg = main() print msg mainloop()