def draw_circle(diameter, color):
    return Circle(width=diameter, height=diameter, color=color)

circles = [draw_circle(150, "white"),
           draw_circle(120, "black"), 
           draw_circle(90, "blue"),
           draw_circle(60, "red"),
           draw_circle(30, "yellow"),
           draw_circle(0, "white")]

colors = ["black", "blue", "red", "yellow", "white"]

growth = [150, 120, 90, 60, 30]
for i in range(5):
	with animation(duration=0.5):
		for n,circle in enumerate(circles[1:]):
			circle.width = growth[n]
			circle.height = growth[n]
            
            
		del circles[0]
        circles.append(draw_circle(0, color=colors[i]))