Django Signals

models.py

from django.db import models
from django.contrib.auth.models import User

class Person(models.Model):
	employee_id = models.IntegerField(unique=True,editable=False)
	username = models.CharField(max_length=50,unique=True,editable=False)
	state_id = models.IntegerField(unique=True,null=True,blank=True,editable=False)
	email = models.EmailField(max_length=50,unique=True,editable=False)
	firstname = models.CharField(max_length=50,editable=False)
	lastname = models.CharField(max_length=50,editable=False)
	telephone = models.CharField(max_length=25,editable=False)
	date_added = models.DateTimeField('date_added',auto_now_add=True, editable=False)
	date_updated = models.DateTimeField('date_updated',auto_now_add=True, auto_now=True, editable=False)
	django_user = models.ForeignKey(User,null=True,blank=True)
	def __unicode__(self):
		return u'%s' % (self.username)

signals.py

from django.db import models
from personnel.models import *

def user_post_delete(sender, instance, **kwargs):
    try:
    	person_item = Person.objects.get(username = instance.username)
    	person_item.django_user = None
        person_item.save()
    except:
        pass

def user_post_save(sender, instance, **kwargs):
    try:
        person_item = Person.objects.get(username = instance.username)
    	person_item.django_user = instance
        person_item.save()
    except:
        pass

models.signals.post_delete.connect(user_post_delete, sender=User)
models.signals.post_save.connect(user_post_save, sender=User)