lst=[[1,2],[4,5],[3,4],[4,3],[2,1],[1,2]]
fset = set(frozenset(x) for x in lst)
lst = [list(x) for x in fset]
This won't preserve order from your original list, nor will it preserve order of your sublists.
>>> lst=[[1,2],[4,5],[3,4],[4,3],[2,1],[1,2]]
>>> fset = set(frozenset(x) for x in lst)
>>> lst = [list(x) for x in fset]
>>> lst
[[1, 2], [3, 4], [4, 5]]
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