Python base n en/de-coder class - Based on http://stackoverflow.com/questions/1119722/base-62-conversion-in-python

base.py

BINARY = '01'
OCTAL = '01234567'
DECIMAL = '0123456789'
HEXADEC = '0123456789ABCDEF'
BASE_62 = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'

rev = lambda x: dict((c, i) for i, c in enumerate(x))
used = BASE_62

def encode(NUM, base=used):
    ret = ''
    factor = ''
    blen = len(base)
    if NUM < 0:
        NUM *= -1
        factor = '-'
    while NUM != 0:
        ret += base[NUM % blen]
        NUM //= blen
    return factor + ret[::-1]

def decode(STR, base=used):
    ret = 0
    factor = 1
    rbase = rev(base)
    blen = len(base)
    if STR[0] == '-':
        STR = STR[1:]
        factor = -1
    for i, c in enumerate(reversed(STR)):
        ret += (blen ** i) * rbase[c]
    return factor * ret