1. import pygame, random, sys, math
2.  
3. # You have to call this to make it work.
4. pygame.init()
5.  
6. # Set up some variables containing the screeen size
7. sizeX=600
8. sizeY=600
9.  
10. # Set the starting colour
11. colour = pygame.Color('#009900')
12.  
13. # Create the pygame window
14. window = pygame.display.set_mode([sizeX,sizeY])
15.  
16. # Create the clock object
17. clock = pygame.time.Clock()
18.  
19. # Put a name on the window.
20. pygame.display.set_caption("Spirograph")
21.  
22. # Initialise more variables
23. # k and l are numbers between 0 and 1.
24. # k is the ratio of the distance of the small circle from the big circle
25. l=random.random()
26.  
27. # l is the ratio of the small circles radius (to the hole with the pen in)
28. # to the distance from the centre of the large circle.
29. k=random.random()
30.  
31. # Counter - real number - not integer.
32. i=0.0
33.  
34. # Scaling factor (Radius of big circle)
35. R=300
36.  
37. x=0
38. y=0
39.  
40. # This will loop forever.
41. while True:
42.     t = math.radians(i)
43.  
44.     newx = R * ((1-k) * math.cos(t) + l*k*math.cos((1-k) * t / k ))
45.     newy = R * ((1-k) * math.sin(t) - l*k*math.sin((1-k) * t / k ))
46.  
47.     if (x==0 and y==0):
48.        pass
49.     else:
50.        pygame.draw.line(window,colour,(x+R,y+R),(newx+R,newy+R),2)
51.     x=newx
52.     y=newy
53.  
54.     i=i+5
55.  
56.     clock.tick(40)
57.     pygame.display.flip()
58.     for event in pygame.event.get():
59.         if event.type == pygame.QUIT:
60.             sys.exit()
61.         elif event.type == pygame.KEYDOWN:
62.             if event.key == pygame.K_ESCAPE:
63.                 sys.exit()
64. sys.exit()