Given a list, generate all permutations of the items in it.

permutations.py

def permutations(lst):
    return permutations_util(lst, 0)


def permutations_util(lst, index):
    perms = []
    if index == len(lst) - 1:
        perms.append(lst.copy())
    for i in range(index, len(lst)):
        lst[i], lst[index] = lst[index], lst[i]
        perms.extend(permutations_util(lst, index+1))
        lst[i], lst[index] = lst[index], lst[i]
    return perms


num_list = [1, 2, 3]
print(permutations(num_list))
char_list = ['r', 'a', 'm']
print(permutations(char_list))