This was an attempt at finding permutations for an array/list. It works for 4 items, but that's it. Next stop: Heap's algorithm

permutation_attempt.py

def perms(data):
    return_data = []
    counter = 1
    for x in range(1, len(data) + 1):
        counter *= x 
    shapes = [
        [0, 1, 2, 3],
        [0, 1, 3, 2],
        [0, 2, 1, 3],
        [0, 2, 3, 1],
        [0, 3, 1, 2],
        [0, 3, 2, 1],
    ]
    for count in range(0, counter):
        mod = count % len(data)
        div = int(count/ len(data))
        item = []
        for slot in range(0, len(data)):
            item.append(
                data[shapes[div][(slot + mod) % len(data)]]
            )
        return_data.append(item)
    return return_data
        
results = perms(['a', 'b', 'c', 'd'])

for result in results:
    print(result)