Solucion limpia de circulo 101027

while True:
    lienzo.delete('all')
    lienzo.create_oval(x+10,40,x+100,100,fill = 'blue')
    if (x>300 or x <0):
        direction =direction*(-1)
    x+=1*direction
    lienzo.after(200)
    lienzo.update()

main loop()