Generate list of all possible permutations of a string

Question

How would I go about generating a list of all possible permutations of a string between x and y characters in length, containing a variable list of characters.

Any l

Answer 1

Non recursive solution according to Knuth, Python example:

def nextPermutation(perm):
    k0 = None
    for i in range(len(perm)-1):
        if perm[i]