diminishing_combinations.py

from itertools import combinations

def diminishing_combinations(arr: list):
    for i in range(len(arr)):
        for c in combinations(arr, i):
            if len(c) < 1:
                continue

            yield c
    
    yield tuple(arr)

 # Test cases
assert list(diminishing_combinations([])) == [()]
assert list(diminishing_combinations([10])) == [(10,)]
assert list(diminishing_combinations([10, 20])) == [(10,), (20,), (10, 20)]
assert list(diminishing_combinations([10, 20, 30])) == [
    (10,),
    (20,),
    (30,),
    (10, 20),
    (10, 30),
    (20, 30),
    (10, 20, 30),
]
assert list(diminishing_combinations([10, 20, 30, 40])) == [
    (10,),
    (20,),
    (30,),
    (40,),
    (10, 20),
    (10, 30),
    (10, 40),
    (20, 30),
    (20, 40),
    (30, 40),
    (10, 20, 30),
    (10, 20, 40),
    (10, 30, 40),
    (20, 30, 40),
    (10, 20, 30, 40),
]