combos = {'12012011': [1201, 120, 1], '87887': [87, 878], '99713': [97, 9, 
    13], '9955171': [9, 1, 95, 17, 5], '99799713': [97, 9, 13, 979],
    '10100': [100, 10], '13213': [13, 132], '8788717': [87, 17, 878],
    '93621221': [936, 21, 212], '11101110': [1, 1101, 110]}

def test(f):
    for k, v in list(combos.items()):
        print('{} -> {} ({})'.format(v, f(v), 'correct' if f(v) == k else
            'incorrect, should be {}'.format(k)))
test(largestpossible)
Constructing the largest number possible by rearranging a list