permute.py

'permutation program'

def permute(data, size, picked):
    'recursive function'
    if not size:
        res = ''.join(picked)
        print(res)
    else:
        # print(data)
        for element in data:
            new_picked = list(picked)
            new_picked.append(element) # we need a copy of element
            new_data = list(data)
            new_data.remove(element)
            permute(new_data, size-1, new_picked)


def main():
    'main function'
    input_string = 'abcdefgh'
    input_data = list(input_string)
    permute(input_data, 3, [])


if __name__ == '__main__':
    main()