如何在Django中删除模型项并添加新项？

from django.db import models

class Post(models.Model):
    title = models.CharField(max_length=200)
    content = models.TextField()
    pub_date = models.DateTimeField('date published')

# 获取要删除的帖子
post_to_delete = Post.objects.get(id=1)

# 删除帖子
post_to_delete.delete()

# 创建一个新的帖子实例
new_post = Post(title='New Post', content='This is the content of the new post.')

# 保存新的帖子实例到数据库
new_post.save()

try:
    post_to_delete = Post.objects.get(id=1)
    post_to_delete.delete()
except Post.DoesNotExist:
    print("Post does not exist")

try:
    new_post = Post(title='New Post', content='This is the content of the new post.')
    new_post.save()
except IntegrityError:
    print("Post with this title already exists")