class Comment(models.Model):
    post = models.ForeignKey(Post, on_delete=models.CASCADE)
    text = models.TextField()
    time_created = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return 'The post is {0}, ID is {1}'.format(Post.objects.get(pk=self.post.pk), self.post.pk)