>>> import random
>>> q = range(16)
>>> for _ in xrange(32):
...   items = [random.choice(q) for _ in range(5)]
...   print len(items) == len(set(items)) or items
...
[4, 5, 12, 7, 12]
[4, 9, 9, 11, 5]
True
True
True
True
[1, 1, 1, 5, 15]
True
[14, 6, 11, 11, 14]
[1, 9, 8, 1, 6]
True
[11, 8, 1, 11, 7]
[15, 14, 2, 15, 3]
[5, 1, 9, 3, 5]
True
[4, 4, 9, 9, 0]
[7, 15, 5, 8, 5]
True
True
[14, 9, 4, 12, 9]
[4, 11, 11, 7, 0]
[10, 9, 4, 12, 4]
True
True
[9, 3, 4, 1, 9]
True
[1, 4, 12, 7, 4]
[4, 9, 4, 8, 8]
[4, 10, 4, 4, 2]
True
True
True