Given a list of chars, generate all possible permutations of the chars where the chars can repeat. Equivalent (should be) to itertools.product(chars, repeat=num_chars)

list_product.py

def password_gen(num_chars, chars):
    """
    This is a generator
    that outputs all passwords of lowercase letters of length
    num_chars.

    Inputs:
    num_chars- the length of the password
    chars- a list of the characters that can be part of the password
    """
    if num_chars == 0:
        yield ''
    else:
        for password in password_gen(num_chars-1, chars):
            for char in chars:
                yield char + password

def password_gen_list(num_chars, chars):
    if num_chars == 1:
        return chars
    else:
        passwords = []
        for password in password_gen(num_chars-1, chars):
            for char in chars:
                passwords.append(char + password)
        return passwords