class Question(models.Model):
    question_text = models.CharField(max_length=400)
    def __unicode__(self):              # __unicode__ on Python 2
        return self.question_text

class Mytest(models.Model):
    mytest_name = models.CharField(max_length=400)
    pub_date = models.DateTimeField('Дата:')
    question = models.ManyToManyField(Question, verbose_name="Вопросы")
    def __unicode__(self):              # __unicode__ on Python 2
        return self.mytest_name

class Choice(models.Model):
    choice_text = models.CharField(max_length=400)
    question = models.ForeignKey(Question)
    ANSWER_CHOICES = (
            ('1', 'Правильный ответ'),
            ('0', 'Неправильный ответ'),
        )
    answer = models.CharField(max_length=1, choices=ANSWER_CHOICES, default=0)
    def __unicode__(self):             # __unicode__ on Python 2
        return self.choice_text