code: def diff_identifiers(a, b):
      
  
      a_ids = set(a.identifiers)
      b_ids = set(b.identifiers)
  
      difference = []
  
      for i in a_ids.difference(b_ids):
          difference.append((i, True, False))
      for i in b_ids.difference(a_ids):
          difference.append((i, False, True))
  
      return difference
docs: Return list of tuples where identifiers in datasets differ.
  
      Tuple structure:
      (identifier, present in a, present in b)
  
      :param a: first :class:`dtoolcore.DataSet`
      :param b: second :class:`dtoolcore.DataSet`
      :returns: list of tuples where identifiers in datasets differ