在Django Rest Framework中按模型属性排序时如何避免重新计算

我有一个简单的社交媒体应用程序，与用户，帖子，投票后模型.

class Post(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    user = models.ForeignKey(User, on_delete=models.SET_NULL, null=True)
    
    ...

    @property
    def score(self):
        total = 0
        for vote in PostVote.objects.all():
            if vote.post == self:
                total += vote.vote
        return total
   
    def get_num_upvotes(self):
        return PostVote.objects.filter(post=self, vote=1).count()

    def get_num_downvotes(self):
        return PostVote.objects.filter(post=self, vote=-1).count()


class PostVote(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    user = models.ForeignKey(User, on_delete=models.SET_NULL, null=True)
    post = models.ForeignKey(Post, on_delete=models.SET_NULL, null=True)
    vote = models.IntegerField()

在我的views.py中，我试图计算出排名靠前的帖子，并按分数排序.以下是视图代码.

class ListCreatePostAPIView(ListCreateAPIView):
    serializer_class = PostSerializer
    permission_classes = (IsGoodUser | IsAdminUser,)

    def get_queryset(self):
        try:
            queryset = Post.objects.all().exclude(user=None)
            queryset = list(queryset)
            queryset.sort(key=operator.attrgetter("score"), reverse=True)
            return queryset
        except:
            return Post.objects.none()

在序列化程序中，我还会再次重新计算并返回分数，因为我希望将它传递给我的前端.

class PostSerializer(serializers.ModelSerializer):
    score = serializers.SerializerMethodField()
    num_upvotes = serializers.SerializerMethodField()
    num_downvotes = serializers.SerializerMethodField()

    def get_score(self, obj):
        return obj.get_score()

    def get_num_upvotes(self, obj):
        return obj.get_num_upvotes()

    def get_num_downvotes(self, obj):
        return obj.get_num_downvotes()

    class Meta:
        model = Post
        fields = (
            "score",
            "num_upvotes",
            "num_downvotes",
        )

我知道我重新计算分数的次数太多了，因为返回50个虚假帖子/1250个虚假帖子需要3-4秒，但我如何才能真正提高效率呢？我try 过PREFETCH_Related，但我想不出如果对属性进行排序该如何使用它.我真的迷路了，如果有任何帮助，我将不胜感激.