1. a = [1,2]
  2.  
  3. for ctr in range(0,len(a)):
  4. print ctr
  5. if len(a) < 10:
  6. a.append(2)
  7.  
  8. while len(a) < 10:
  9. a.append(2)
  10.  
  11. a.extend([2] * (10 - len(a)))
  12.  
  13. a += [2] * (10 - len(a))
  14.  
  15. a += [2] * (10 - len(a))
  16.  
  17. a = [1,2]
  18. while len(a) < 10:
  19. a.append(2)
  20.  
  21. >>> from itertools import chain, islice, repeat
  22. >>> list(islice(chain(a, repeat(2)), 10))
  23. [1, 2, 2, 2, 2, 2, 2, 2, 2, 2]