text: from django.db import models
  
  
  class CustomerManager(models.Manager):
  
      def get_queryset(self):
          return super(CustomerManager, self).get_queryset().filter(person_type='c')
  
  
  class PersonManager(models.Manager):
  
      def get_queryset(self):
          return super(PersonManager, self).get_queryset().filter(person_type='p')
  