old_contents: from django.contrib import admin
  
  from .models import Post
  
  
  @admin.register(Post)
  class PostAdmin(admin.ModelAdmin):
      date_hierarchy = 'pub_date'
      list_display = ('title', 'pub_date')
      list_filter = ('pub_date',)
  
new_contents: from django.contrib import admin
  
  from .models import Post
  
  
  @admin.register(Post)
  class PostAdmin(admin.ModelAdmin):
      date_hierarchy = 'pub_date'
      list_display = ('title', 'pub_date')
      list_filter = ('pub_date',)
      search_fields = ('title', 'text')
  
subject: Define PostAdmin search_fields.