gistfile1.py

>>> def test_loop(previous_quarter, quarter_index, max_quarter):
...     while previous_quarter % max_quarter != quarter_index:
...             print(previous_quarter % max_quarter)
...             previous_quarter+=1
... 
>>> 
>>> test_loop(10,10,20)
>>> test_loop(10,11,20)
10
>>> test_loop(10,12,20)
10
11