如果订单重要，您可以随时使用OrderedDict

If the Order Matters you can always use OrderedDict

>>> unq_lst = OrderedDict()
>>> for e in lst:
    unq_lst.setdefault(frozenset(e),[]).append(e)


>>> map(list, unq_lst.keys())
[[1, 2], [4, 5], [3, 4]]