Improving my random password generator in Python

Learning Python is a great programming experience. The immediacy of the environment lends itself perfectly to experimentation, trying out new things and a very iterative approach to coding.

Previously I wrote a random password generator in Python. This worked well, but had a couple of problems. The first, identified at the time, was that there was a slight bias in the algorithm which would return certain characters more often than others. A second problem, identified after some pondering, was the inclusion of some redundant code. That version of the function had three lists and a dictionary - could this be consolidated down to just the dictionary? As it happens... YES!

The typical usage of dictionaries is to pass in a key to obtain a value. However, it's perfectly possible to obtain a key, value or both by supplying an index using a dictionary's .keys(), .values() or .items() methods and supplying the index such as:

phoneticDictionary.items()[15]

This means, of course, that it would be possible to get a randomly generated index from the dictionary, like so:

phoneticDictionary.items()[random.randint(0, 61)]

Knowing this meant I was able to alter my code to get rid of the three lists and use just the dictionary itself. It also got rid of the bias noted earlier.

Here's the complete listing:

import random

def getRandomPassword(length):
    phoneticDictionary = {"A" : "ALPHA",
                          "B" : "BRAVO",
                          "C" : "CHARLIE",
                          "D" : "DELTA",
                          "E" : "ECHO",
                          "F" : "FOXTROT",
                          "G" : "GOLF",
                          "H" : "HOTEL",
                          "I" : "INDIA",
                          "J" : "JULIET",
                          "K" : "KILO",
                          "L" : "LIMA",
                          "M" : "MIKE",
                          "N" : "NOVEMBER",
                          "O" : "OSCAR",
                          "P" : "PAPA",
                          "Q" : "QUEBEC",
                          "R" : "ROMEO",
                          "S" : "SIERRA",
                          "T" : "TANGO",
                          "U" : "UNIFORM",
                          "V" : "VICTOR",
                          "W" : "WHISKEY",
                          "X" : "XRAY",
                          "Y" : "YANKEE",
                          "Z" : "ZULU",
                          "a" : "alpha",
                          "b" : "bravo",
                          "c" : "charlie",
                          "d" : "delta",
                          "e" : "echo",
                          "f" : "foxtrot",
                          "g" : "golf",
                          "h" : "hotel",
                          "i" : "india",
                          "j" : "juliet",
                          "k" : "kilo",
                          "l" : "lima",
                          "m" : "mike",
                          "n" : "november",
                          "o" : "oscar",
                          "p" : "papa",
                          "q" : "quebec",
                          "r" : "romeo",
                          "s" : "sierra",
                          "t" : "tango",
                          "u" : "uniform",
                          "v" : "victor",
                          "w" : "whiskey",
                          "x" : "xray",
                          "y" : "yankee",
                          "z" : "zulu",
                          "0" : "Zero",
                          "1" : "One",
                          "2" : "Two",
                          "3" : "Three",
                          "4" : "Four",
                          "5" : "Five",
                          "6" : "Six",
                          "7" : "Seven",
                          "8" : "Eight",
                          "9" : "Nine"}

    password = []
    phoneticPassword = []                          
    for i in range(length):
        c, pc = phoneticDictionary.items()[random.randint(0, 61)]
        password.append(c)
        phoneticPassword.append(pc)

    return "".join(password), "-".join(phoneticPassword)

And here's the function's output run 10 times specifying a length of 8:

pnReI0lg papa-november-ROMEO-echo-INDIA-Zero-lima-golf
7g7SnNKl Seven-golf-Seven-SIERRA-november-NOVEMBER-KILO-lima
7Q3Zy4Ya Seven-QUEBEC-Three-ZULU-yankee-Four-YANKEE-alpha
697vxMRX Six-Nine-Seven-victor-xray-MIKE-ROMEO-XRAY
R214zUMk ROMEO-Two-One-Four-zulu-UNIFORM-MIKE-kilo
f0db3LbG foxtrot-Zero-delta-bravo-Three-LIMA-bravo-GOLF
IC9046VT INDIA-CHARLIE-Nine-Zero-Four-Six-VICTOR-TANGO
8mg5Vufa Eight-mike-golf-Five-VICTOR-uniform-foxtrot-alpha
C2Puu9dc CHARLIE-Two-PAPA-uniform-uniform-Nine-delta-charlie
tcK6OCsG tango-charlie-KILO-Six-OSCAR-CHARLIE-sierra-GOLF