import random
from collections import defaultdict
d = defaultdict(int)
for i in xrange(10000):
  d[tuple(sorted((random.choice(['b','g']), random.choice(['b','g']))))] += 1
for k,v in d.items():
  print k,v

('b', 'b') 2508
('b', 'g') 4986
('g', 'g') 2506