old_contents: from django.db import models
  
  
  class Question(models.Model):
      question_text = models.CharField(max_length=200)
      pub_date = models.DateTimeField('date published')
  
      def __unicode__(self):
          return self.question_text
  
      def was_published_recently(self):
          return self.pub_date >= timezone.now() - datetime.timedelta(days=1)
  
  
  class Choice(models.Model):
      question = models.ForeignKey(Question)
      choice_text = models.CharField(max_length=200)
      votes = models.IntegerField(default=0)
  
      def __unicode__(self):
          return self.choice_text
  
new_contents: from django.db import models
  
  
  class Question(models.Model):
      question_text = models.CharField(max_length=200)
      pub_date = models.DateTimeField('date published')
  
      def __str__(self):
          return self.question_text
  
      def was_published_recently(self):
          return self.pub_date >= timezone.now() - datetime.timedelta(days=1)
  
  
  class Choice(models.Model):
      question = models.ForeignKey(Question)
      choice_text = models.CharField(max_length=200)
      votes = models.IntegerField(default=0)
  
      def __str__(self):
          return self.choice_text
  
subject: Switch to python3