In your settings.py

   INSTALLED_APPS = (
       'django.contrib.auth',
       'django.contrib.contenttypes',
       'django.contrib.sessions',
       'django.contrib.sites',
       'django.contrib.admin',

       ...

       'smartextends',

   )

and if you want:

OVERWRITE_EXTENDS = True

How to use

This application is useful when you want to overwrite a template of a application in your project. Currently this in Django produce infinite recursion

If you don't set OVERWRITE_EXTENDS = True

file:admin/change_list.html

{% extends "admin/change_list.html" %}

{% block extrastyle %}
    {{ block.super }}
    <link rel="stylesheet" type="text/css" href="XXX" />
{% endblock %}

Else:

file:admin/change_list.html

{% smart_extends "admin/change_list.html" %}

{% block extrastyle %}
    {{ block.super }}
    <link rel="stylesheet" type="text/css" href="XXX" />
{% endblock %}