gen_code.py

# -*- coding: utf-8 -*-
from __future__ import unicode_literals
from random import SystemRandom
import sys
import re

system_random = SystemRandom()


def base36_to_int(s):
    if len(s) > 13:
        raise ValueError("Base36 input too large")
    value = int(s, 36)
    if value > sys.maxint:
        raise ValueError("Base36 input too large")
    return value


def int_to_base36(i):
    digits = "0123456789abcdefghijklmnopqrstuvwxyz"
    factor = 0
    if not 0 <= i <= sys.maxint:
        raise ValueError("Base36 conversion input too large or incorrect type.")
    # Find starting factor
    while True:
        factor += 1
        if i < 36 ** factor:
            factor -= 1
            break
    base36 = []
    # Construct base36 representation
    while factor >= 0:
        j = 36 ** factor
        base36.append(digits[i // j])
        i = i % j
        factor -= 1
    return ''.join(base36)


def generateCode(count=100):
    """Base 36 is the most compact case-insensitive alphanumeric numeral system using ASCII characters"""
    low = base36_to_int('100000000000')
    high = base36_to_int('zzzzzzzzzzzz')
    cnt = 0
    for i in xrange(count*10):
        if cnt > count:
            break
        slug = int_to_base36(system_random.randint(low, high))
        fuzzy_letter = re.compile(r'.*?[o0i1]+?.*', re.IGNORECASE)
        if not fuzzy_letter.match(slug):
            cnt += 1
            code = []
            for i in xrange(0, len(slug), 4):
                code.append(slug[i:i + 4])
            yield u'-'.join(code).upper()

if __name__ == "__main__":
    codes = generateCode(int(sys.argv[1]))
    for c in codes: print c