text: from django.contrib import admin
  from .models import Post, Category, Tag
  
  class PostAdmin(admin.ModelAdmin):
      list_display = ['title', 'created_time', 'modified_time', 'category', 'author']
  
  # 把新增的 PostAdmin 也注册进来
  admin.site.register(Post, PostAdmin)
  admin.site.register(Category)
  admin.site.register(Tag)
  