gistfile1.txt

Question: Convert following into the latter data structure in less than 30 lines:

List:
  A, B, C
  A, C, E
  E, F, D
  D, A, J
  E, D, J

List
  A, B, 1 (frequency)
  A, C, 2
  A, D, 1
  A, E, 1
  A, J, 1
  B, C, 1
  C, E, 1
  D, E, 2
  D, F, 1
  D, J, 2
  E, F, 1
  E, J, 1

solution.py

from itertools import combinations

x = [('a', 'b', 'c'), ('a', 'c', 'e'), ('e', 'f', 'd'), ('d', 'a', 'j'), ('e', 'd', 'j')]
counts = {}
for row in x:
    for combo in combinations(row, 2):
        combo = tuple(sorted(combo))
        counts[combo] = counts.get(combo, 0) + 1
result = [(combo[0], combo[1], count) for combo, count in sorted(counts.iteritems(), key=lambda item: item[0])]