list approach due nested order

[stranac]

Since the order doesn't matter, you might want to consider using a set of frozensets:

>>> unique = set()
>>> unique.add(frozenset(['a', 'b']))
>>> unique.add(frozenset(['b', 'a']))
>>> unique.add(frozenset([1, 2]))
>>> unique
{frozenset({'a', 'b'}), frozenset({1, 2})}