# Tk_ani_mosaic.py

# Tk_ani_mosaic.py

import Tkinter as tk
import random

r = tk.Tk()

c = tk.Canvas(r, width=200, height=210)
c.pack(fill=tk.BOTH, expand=tk.YES)

# draw 400 rectangles
objs = []
for i in range(20):
    for j in range(20):
        obj = c.create_rectangle(i*10, j*10, i*10+10, j*10+10,
fill='#888888', outline='#888888')
        objs.append(obj)

def run():
    # loop indefinitely and randomly change the canvas item colours
    while True:
        obj = random.choice(objs)
        red = random.randint(0,255)
        green = random.randint(0,255)
        blue = random.randint(0,255)
        colour = '#%02x%02x%02x' %(red, green, blue)
        c.itemconfigure(obj, fill=colour, outline=colour)
        r.update()

tk.Button(r, text='Run', command=run).pack()

r.mainloop()