django extend admin

admin.py

from django.contrib import admin
from django.contrib.admin import AdminSite
from django.contrib.auth.models import User, Group
from . models import Book

class MyAdminSite(AdminSite):
    site_header = 'New Admin Interface'
    
admin_site = MyAdminSite(name='new_admin')

admin_site.register(User)
admin_site.register(Group)
admin_site.register(Book)

urls.py

from django.conf.urls import url
from upload.admin import admin_site

urlpatterns = [
              url(r'^admin/', admin_site.urls), 
              # url(r'^admin/', admin.site.urls), 
              ...
              ]