old_contents: from django.db import models
  from django.contrib.auth.models import User
  
  
  class Poll(models.Model):
      question = models.CharField(max_length=255)
      description = models.TextField(blank=True)
  
      def count_choices(self):
          return self.choice_set.count()
  
      def count_total_votes(self):
          result = 0
          for choice in self.choice_set.all():
              result += choice.count_votes()
          return result
  
      def can_vote(self, user):
          return not self.vote_set.filter(user=user).exists()
  
      def __unicode__(self):
          return self.question
  
  
  class Choice(models.Model):
      poll = models.ForeignKey(Poll)
      choice = models.CharField(max_length=255)
  
      def count_votes(self):
          return self.vote_set.count()
  
      def __unicode__(self):
          return self.choice
  
      class Meta:
          ordering = ['choice']
  
  
  class Vote(models.Model):
      user = models.ForeignKey(User)
      poll = models.ForeignKey(Poll)
      choice = models.ForeignKey(Choice)
  
      def __unicode__(self):
          return u'Vote for %s' % (self.choice)
  
      class Meta:
          unique_together = (('user', 'poll'))
  
new_contents: from django.db import models
  from django.conf import settings
  
  
  class Poll(models.Model):
      question = models.CharField(max_length=255)
      description = models.TextField(blank=True)
  
      def count_choices(self):
          return self.choice_set.count()
  
      def count_total_votes(self):
          result = 0
          for choice in self.choice_set.all():
              result += choice.count_votes()
          return result
  
      def can_vote(self, user):
          return not self.vote_set.filter(user=user).exists()
  
      def __unicode__(self):
          return self.question
  
  
  class Choice(models.Model):
      poll = models.ForeignKey(Poll)
      choice = models.CharField(max_length=255)
  
      def count_votes(self):
          return self.vote_set.count()
  
      def __unicode__(self):
          return self.choice
  
      class Meta:
          ordering = ['choice']
  
  
  class Vote(models.Model):
      user = models.ForeignKey(settings.AUTH_USER_MODEL)
      poll = models.ForeignKey(Poll)
      choice = models.ForeignKey(Choice)
  
      def __unicode__(self):
          return u'Vote for %s' % (self.choice)
  
      class Meta:
          unique_together = (('user', 'poll'))
  
subject: Support for custom user model