data = [ (1, ["apple", "banana", "cherry"]), (2, ["banana", "cherry", "apple"]), # тот же набор (3, ["apple", "banana"]), (4, ["cherry", "apple"]), # другой набор (5, ["apple", "banana", "cherry"]), # третий с тем же набором [ (["apple", "banana", "cherry"], [1,2,5]), (["apple","banana"], [3]), (["apple","cherry"], [4]) ] from collections import defaultdict def get_users_and_baskets(fruits_baskets): data = defaultdict(list) for user, basket in fruits_baskets: key = frozenset(basket) data[key].append(user) return sorted(data.values(), key=len, reverse=True) print(get_users_and_baskets(data))