code: def to_dictionary(pw, print_list):
      
      pairs = {}
      for p in pw:
          a, b, pident = p
          if a not in pairs:
              pairs[a] = {a: '-'}
          if b not in pairs:
              pairs[b] = {b: '-'}
          pairs[a][b] = pident
          pairs[b][a] = pident
          if print_list is True:
              A, B = a.split('>')[1], b.split('>')[1]
              print('\t'.join([str(i) for i in [A, B, pident]]), file=sys.stderr)
              print('\t'.join([str(i) for i in [B, A, pident]]), file=sys.stderr)
      return pairs
docs: - convert list of comparisons to dictionary
      - print list of pidents (if requested) to stderr