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 collections import Counter
from itertools import combinations, chain
from operator import itemgetter

rows = [
    ["A", "B", "C"],
    ["A", "C", "E"],
    ["E", "F", "D"],
    ["D", "A", "J"],
    ["E", "D", "J"]
]

combos = list(chain(*(map(lambda row: combinations(row, 2), rows))))
result = [(k[0], k[1], v) for k, v in sorted(sorted(Counter(combos).items(), key=itemgetter(1)), key=lambda x: x[0])]