A script to generate a random numeric pin along with a string of possible ‘phone keyboard phrases’ (using the letters shown on a phone keyboard, setting 1 to punctuation and 0 to language-specific letters).

mnemonic_pin.py

from random import choice

available_numbers = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "0"]

numbers_to_letters = {"1":["."], 
                      "2":["A", "B", "C"], 
                      "3":["D", "E", "F"], 
                      "4":["G", "H", "I"], 
                      "5":["J", "K", "L"], 
                      "6":["M", "N", "O"], 
                      "7":["P", "Q", "R", "S"], 
                      "8":["T", "U", "V"], 
                      "9":["W", "X", "Y", "Z"], 
                      "0":["Æ", "Ø", "Å"]}


def generate_pin(length=4):
    pin = ""
    for i in range(length):
        pin += choice(available_numbers)

    return pin


def generate_mnemomic_phrase(numbers, prefix_string=""):
    if not numbers:
        print(prefix_string)
    else:
        for l in numbers_to_letters[numbers[0]]:
            generate_mnemomic_phrase(numbers[1:], prefix_string + l)


if __name__ == "__main__":
    a = generate_pin()
    print(a)
    generate_mnemomic_phrase(a)