def print_all_subsets(original_set):
    def _print_subset(arr, original_set):
        res = ''
        for i in xrange(len(arr)):
            if arr[i] == 1:
                res += str(original_set[i]) + ' '
        print res

    def _recursion(depth, arr, original_set):
        if depth == len(arr):
            _print_subset(arr, original_set)
            return

        for i in [0, 1]:
            arr[depth] = i
            _recursion(depth + 1, arr, original_set)


    _recursion(0, [0 for i in range(len(original_set))], original_set)


arr = ['a', 'b', 'f', 'i', 'w']
print_all_subsets(arr)