# Brownian motion -- an example of a multi-threaded Tkinter program. from Tkinter import * import random import threading import time import sys WIDTH = 400 HEIGHT = 300 SIGMA = 10 BUZZ = 2 RADIUS = 2 LAMBDA = 10 FILL = 'red' stop = 0 # Set when main loop exits def particle(canvas): r = RADIUS x = random.gauss(WIDTH/2.0, SIGMA) y = random.gauss(HEIGHT/2.0, SIGMA) p = canvas.create_oval(x-r, y-r, x+r, y+r, fill=FILL) while not stop: dx = random.gauss(0, BUZZ) dy = random.gauss(0, BUZZ) dt = random.expovariate(LAMBDA) try: canvas.move(p, dx, dy) except TclError: break time.sleep(dt) def main(): global stop root = Tk() canvas = Canvas(root, width=WIDTH, height=HEIGHT) canvas.pack(fill='both', expand=1) np = 30 if sys.argv[1:]: np = int(sys.argv[1]) for i in range(np): t = threading.Thread(target=particle, args=(canvas,)) t.start() try: root.mainloop() finally: stop = 1 main()