Formats the RUT form to the common string representation.

format_rut.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from django import template
register = template.Library()

from django.utils.encoding import smart_unicode

def _verifier(rut):
    rut = smart_unicode(rut).replace(' ', '').replace('.', '').replace('-', '')
    return rut[:-1], rut[-1].upper()

def _format(code, verifier):
    while len(code) > 3 and '.' not in code[:3]:
        pos = code.find('.')
        if pos == -1:
            new_dot = -3
        else:
            new_dot = pos - 3
        code = code[:new_dot] + '.' + code[new_dot:]
    return u'%s-%s' % (code, verifier)

@register.filter(name='rut_format')
def rut_format(value):
    rut, verificador = _verifier(value)
    return _format(rut, verificador)