| #!/usr/bin/env python3 | 
 |  | 
 | """ | 
 | A Python version of the classic "bottles of beer on the wall" programming | 
 | example. | 
 |  | 
 | By Guido van Rossum, demystified after a version by Fredrik Lundh. | 
 | """ | 
 |  | 
 | import sys | 
 |  | 
 | n = 100 | 
 | if sys.argv[1:]: | 
 |     n = int(sys.argv[1]) | 
 |  | 
 | def bottle(n): | 
 |     if n == 0: return "no more bottles of beer" | 
 |     if n == 1: return "one bottle of beer" | 
 |     return str(n) + " bottles of beer" | 
 |  | 
 | for i in range(n, 0, -1): | 
 |     print(bottle(i), "on the wall,") | 
 |     print(bottle(i) + ".") | 
 |     print("Take one down, pass it around,") | 
 |     print(bottle(i-1), "on the wall.") |