FizzBuzz type problem: add commas to an integer.

addcommas.py

from __future__ import division


def addcomas(n, sep=1000):
    cad = ''

    if n < sep:
        return n

    while(n > 0):
        cad = str(n % sep) + cad
        n = n // sep

        if n > 0:
            cad = ',' + cad

    return cad


def addcomas(n):
    cad = str(n)
    l = len(cad)
    start = 3

    while start < l:
        cad = cad[:l-start] + ',' + cad[l-start:]
        start += 3
    return cad





print addcomas(1234567890)
print addcomas(90)
print addcomas(12111111234567890)