code: def identifier_list_cmp(a, b):
      
      identifier_pairs = zip(a, b)
      for id_a, id_b in identifier_pairs:
          cmp_res = identifier_cmp(id_a, id_b)
          if cmp_res != 0:
              return cmp_res
      # alpha1.3 < alpha1.3.1
      return base_cmp(len(a), len(b))
docs: Compare two identifier list (pre-release/build components).
  
      The rule is:
          - Identifiers are paired between lists
          - They are compared from left to right
          - If all first identifiers match, the longest list is greater.
  
      >>> identifier_list_cmp(['1', '2'], ['1', '2'])
      0
      >>> identifier_list_cmp(['1', '2a'], ['1', '2b'])
      -1
      >>> identifier_list_cmp(['1'], ['1', '2'])
      -1