# -*- coding: utf-8-*-


def validate_cuit(cuit):
    "from: http://python.org.ar/pyar/Recetario/ValidarCuit by Mariano Reingart"
    # validaciones minimas
    if len(cuit) != 13 or cuit[2] != "-" or cuit [11] != "-":
        return False

    base = [5, 4, 3, 2, 7, 6, 5, 4, 3, 2]

    cuit = cuit.replace("-", "")

    # calculo digito verificador
    aux = 0
    for i in range(10):
        aux += int(cuit[i]*base[i])

    aux = 11 - (aux - (int(aux/11) * 11))

    if aux == 11:
        aux = 0
    if aux == 10:
        aux = 9

    return aux == int(cuit[10])

Add cuit validator to utils module