Python – Remove duplicate list tuples from the list

I want to write a script to get the list of categories and return the only way to divide the categories into 2 groups. Now I have its tuple form (list_a, list_b), where the union of list_a and list_b represents the complete list of categories.

Below I show an example of a category [‘A’, ‘B’,’C’,’D’] where I can get all groups. However, some are duplicates ([‘A’], [‘B’, ‘C’, ‘D’]) denote the same as ([‘B’, ‘C’, ‘D’], [‘A’]). Also What is a better title for this article?

import itertools
def getCompliment(smallList, fullList):
    compliment = list()
    for item in fullList:
        if item not in smallList:
            compliment.append(item)
    return compliment

optionList = ['A','B','C','D']
combos = list()
for r in range(1,len(optionList)):
    tuples = list(itertools.combinations(optionList, r))
    for t in tuples:
        combos.append((list(t),getCompliment(list(t), optionList)))

print(combos)

[(['A'], ['B', 'C', 'D']),
 (['B'], ['A', 'C', 'D']), 
 (['C'], ['A', 'B', 'D']),
 (['D'], ['A', 'B', 'C']),
 (['A', 'B'], ['C', 'D']),
 (['A', 'C'], ['B', 'D']),
 (['A', 'D'], ['B', 'C']),
 (['B', 'C'], ['A', 'D']),
 (['B', 'D'], ['A', 'C']),
 (['C', 'D'], ['A', 'B']),
 (['A', 'B', 'C'], ['D']),
 (['A', 'B', 'D'], ['C']),
 (['A', 'C', 'D'], ['B']),
 (['B', 'C', 'D'], ['A'])]

I need the following:

[(['A'], ['B', 'C', 'D']),
 (['B'], ['A', 'C', 'D']), 
 (['C'], ['A', 'B', 'D']),
 (['D'], ['A', 'B', 'C']),
 (['A', 'B'], ['C', 'D']),
 (['A', 'C'], ['B', 'D']),
 (['A', 'D'], ['B', 'C'])]

You are very close. What you need is a set of results.

Because the set element must be hashable and the list object is non-hashable, you can use tuple instead. This can be achieved by making some trivial changes to the code.

import itertools

def getCompliment(smallList, fullList):
    compliment = list()
    for item in fullList:
        if item not in smallList:
            compliment.append(item)
    return tuple(compliment)

optionList = ('A','B','C','D')
combos = set()
for r in range(1,len(optionList)):
    tuples = list(itertools.combinations(optionList, r))
    for t in tuples:
        combos.add(frozenset((tuple(t), getCompliment(tuple(t), optionList))))

print(combos)

{frozenset({('A',), ('B', 'C', 'D')}),
 frozenset({('A', 'C', 'D'), ('B',)}),
 frozenset({('A', 'B', 'D'), ('C',)}),
 frozenset({('A', 'B'), ('C', 'D')}),
 frozenset({('A', 'C'), ('B', 'D')}),
 frozenset({('A', 'D'), ('B', 'C')}),
 frozenset({('A', 'B', 'C'), ('D',)})}

If you need to convert the results back to a list of lists, this can be achieved with list understanding:

res = [list(map(list, i)) for i in combos]

[[['A'], ['B', 'C', 'D']],
 [['B'], ['A', 'C', 'D']],
 [['A', 'B', 'D'], ['C']],
 [['A', 'B'], ['C', 'D']],
 [['B', 'D'], ['A', 'C']],
 [['B', 'C'], ['A', 'D']],
 [['A', 'B', 'C'], ['D']]]