#!/usr/bin/env python2.6


def main():
    from Tkinter import Tk, Canvas, BOTH

    root = Tk()
    canvas = Canvas(master=root, background='white')
    canvas.pack(fill=BOTH, expand=1)
    root.geometry("300x200")
    root.resizable(0, 0)

    oval = canvas.create_oval(30, 80, 40, 90, outline='black', fill='red')

    x = 1
    y = 1
    xpos = 35
    ypos = 85

    while True:
        canvas.move(oval, x, y)

        xpos += x
        ypos += y
        if not (295 > xpos > 5):
            x *= -1
        if not (195 > ypos > 5):
            y *= -1

        root.after(10)
        root.update()



if __name__ == '__main__':
    main()