itob.py

import string

_CHARS = string.digits + string.uppercase

def itob(n, base):
    cur_num = n % base
    final = []
    while n > 0:
        final.append(_CHARS[cur_num])
        n /= base
        cur_num = n % base
    final.reverse()
    return "".join(final)


def itob_recur(n, b):
    if n == 0:
        return ""
    final = [_CHARS[n % b], itob_recur(n / b, b)]
    final.reverse()
    return "".join(final)