def _get_unique_parent_pairs(self, pair_list): # translate a list of (entity, entity) tuples to # a list of (parent entity, parent entity) tuples, # thereby removing duplicate (parent entity, parent entity) # pairs. # o pair_list - a list of (entity, entity) tuples parent_pair_list = [] for (e1, e2) in pair_list: p1 = e1.get_parent() p2 = e2.get_parent() if p1 == p2: continue elif p1 < p2: parent_pair_list.append((p1, p2)) else: parent_pair_list.append((p2, p1)) return uniqueify(parent_pair_list)