Question with Choice Serializer dictionary

gistfile1.txt

# polls/models.py
class Question(models.Model):
    ....
    def choices(self):
        if not hasattr(self, '_choices'):
            self._choices = self.choice_set.all()
        return self._choices

# polls/serializers.py
class ChoiceSerializer(serializers.ModelSerializer):

    class Meta:
        model = Choice
        fields = ('id', 'choice_text',)