Synnefo

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import random

getrandbits = random.SystemRandom().getrandbits

DEFAULT_ALPHABET = ("0123456789"

                    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

                    "abcdefghijklmnopqrstuvwxyz")

def get_random_word(length, alphabet=DEFAULT_ALPHABET):

    remainder = getrandbits(length * 8)

    return encode_word(remainder, alphabet=alphabet)

def encode_word(number, alphabet=DEFAULT_ALPHABET):

    base = len(alphabet)

    digits = []

    append = digits.append

    quotient = number

    while True:

        quotient, remainder = divmod(quotient, base)

        append(alphabet[remainder])

        if quotient <= 0:

            break

    return ''.join(digits)