old_contents: from django.contrib import admin
  from app.models import Category, Bookmark, Trash
  
  class CategoryAdmin(admin.ModelAdmin):
  	list_display = ['name', 'user', 'row_number', 'column_number', 'progress_bar_color']
  	list_filter = ['user']
  
  class BookmarkAdmin(admin.ModelAdmin):
  	list_display = ['category', 'name', 'row_number', 'glyphicon', 'id']
  	list_filter = ['category']
  
  class TrashAdmin(admin.ModelAdmin):
  	list_display = ['category', 'name', 'glyphicon', 'id']
  	list_filter = ['category']
  
  admin.site.register(Category, CategoryAdmin)
  admin.site.register(Bookmark, BookmarkAdmin)
  admin.site.register(Trash, TrashAdmin)
new_contents: from django.contrib import admin
  from app.models import Category, Bookmark, Trash
  
  class CategoryAdmin(admin.ModelAdmin):
  	list_display = ['name', 'user', 'row_number', 'column_number', 'progress_bar_color', 'id']
  	list_filter = ['user']
  
  class BookmarkAdmin(admin.ModelAdmin):
  	list_display = ['category', 'name', 'row_number', 'glyphicon', 'id']
  	list_filter = ['category']
  
  class TrashAdmin(admin.ModelAdmin):
  	list_display = ['category', 'name', 'glyphicon', 'id']
  	list_filter = ['category']
  
  admin.site.register(Category, CategoryAdmin)
  admin.site.register(Bookmark, BookmarkAdmin)
  admin.site.register(Trash, TrashAdmin)
subject: Include id in CategoryAdmin for easier debugging