Вот решение, которое не удаляет дубликаты:
from itertools import combinations
a = [4,4,5,6,7]
result = []
for x in range(len(a) + 1):
for left in combinations(a, x):
right = a.copy()
for ele in left:
right.remove(ele)
result.append([list(left), right])
for res in result:
print(res)
Вывод:
[[], [4, 4, 5, 6, 7]]
[[4], [4, 5, 6, 7]]
[[4], [4, 5, 6, 7]]
[[5], [4, 4, 6, 7]]
[[6], [4, 4, 5, 7]]
[[7], [4, 4, 5, 6]]
[[4, 4], [5, 6, 7]]
[[4, 5], [4, 6, 7]]
[[4, 6], [4, 5, 7]]
[[4, 7], [4, 5, 6]]
[[4, 5], [4, 6, 7]]
[[4, 6], [4, 5, 7]]
[[4, 7], [4, 5, 6]]
[[5, 6], [4, 4, 7]]
[[5, 7], [4, 4, 6]]
[[6, 7], [4, 4, 5]]
[[4, 4, 5], [6, 7]]
[[4, 4, 6], [5, 7]]
[[4, 4, 7], [5, 6]]
[[4, 5, 6], [4, 7]]
[[4, 5, 7], [4, 6]]
[[4, 6, 7], [4, 5]]
[[4, 5, 6], [4, 7]]
[[4, 5, 7], [4, 6]]
[[4, 6, 7], [4, 5]]
[[5, 6, 7], [4, 4]]
[[4, 4, 5, 6], [7]]
[[4, 4, 5, 7], [6]]
[[4, 4, 6, 7], [5]]
[[4, 5, 6, 7], [4]]
[[4, 5, 6, 7], [4]]
[[4, 4, 5, 6, 7], []]