Django Twitter的克隆。如何限制用户对一条推文点赞超过一次？

def is_liked_by_user(self, user):
    return self.likes.filter(user=user).exists()

from django.shortcuts import get_object_or_404

def like_tweet(request, tweet_id):
    tweet = get_object_or_404(Tweet, id=tweet_id)
    if not tweet.is_liked_by_user(request.user):
        Like.objects.create(user=request.user, tweet=tweet)
        # 执行其他点赞操作

{% if tweet.is_liked_by_user(request.user) %}
    <button disabled>已点赞</button>
{% else %}
    <button>点赞</button>
{% endif %}