class Comment(CommonCore):
    post = models.ForeignKey(Post, on_delete=models.CASCADE, verbose_name='Родительский пост')
    parent = models.ForeignKey('self', blank=True, null=True, verbose_name='Родительский комментарий')

    def save(self, *args, **kwargs):
        if not self.rating:
            from rating_system.models import Rating
            self.rating = Rating.objects.create()
        super(Comment, self).save(*args, **kwargs)