django rest 框架评论系统

Question

I am trying to build a rest api with django and having hard times with comment system. The API shows my comments correctly but it shows replies to comments twice. One at comments field of post, other at replies field of comments. Like both in depth 1 and 2. So to cut short, there is my code:

-- serializers.py

class CommentChildSerializer(serializers.ModelSerializer):
    parent_id = serializers.PrimaryKeyRelatedField(queryset=Comment.objects.all(),source='parent.id')
    author = SerializerMethodField()
    class Meta:
        model = Comment
        fields = ('author', 'content', 'id','parent_id')

    def get_author(self, obj):
        return obj.author.username

    def create(self, validated_data):
        subject = parent.objects.create(parent=validated_data['parent']['id'], content=validated_data['content'])

class CommentSerializer(serializers.ModelSerializer):
    reply_count = SerializerMethodField()
    author = SerializerMethodField()
    replies = SerializerMethodField()
    class Meta:
        model = Comment
        fields = ('id','content', 'parent', 'author', 'reply_count', 'replies')
        # depth = 1

    def get_reply_count(self, obj):
        if obj.is_parent:
            return obj.children().count()
        return 0

    def get_author(self, obj):
        return obj.author.username

    def get_replies(self, obj):
        if obj.is_parent:
            return CommentChildSerializer(obj.children(), many=True).data
        return None

class PostListSerializer(serializers.ModelSerializer):
    url = post_detail_url
    author = SerializerMethodField()
    image = SerializerMethodField()
    comments = CommentSerializer(required=False, many=True)
    # comments = SerializerMethodField()
    class Meta:
        model = Post
        fields = ('title', 'image', 'author', 'star_rate', 'url', 'slug', 'comments')

    def get_author(self, obj):
         return obj.author.username

    def get_image(self, obj):
        try:
            image = obj.image.url
        except:
            image = None
        return image

-- comment model

class Comment(models.Model):
    post = models.ForeignKey(Post, on_delete=models.CASCADE, related_name='comments')
    author = models.ForeignKey(CustomUser, on_delete=models.CASCADE)
    content = models.TextField(max_length=255)
    created_at = models.DateTimeField(auto_now_add=True)
    parent = models.ForeignKey('self', null=True, blank=True, on_delete=models.CASCADE, related_name='replies')
    is_active = models.BooleanField(default=True)

    class Meta:
        ordering = ('created_at',)

    def __str__(self):
        return f'Comment by {self.author.username} on {self.post}'

    def children(self):
        return Comment.objects.filter(parent=self)

    @property
    def is_parent(self):
        if self.parent is not None:
            return False
        return True

Answer 1

What does your view look like? If you want only comments with no parent to display as top-level comments, then you'll need to make sure that the queryset populating your serializer filters appropriately, eg Comment.objects.filter(parent__isnull=True)