Separating Django installed apps between Development vs Production
<p>I have 3 settings files:</p>

<ul>
<li>base.py (shared)   </li>
<li>development.py   </li>
<li>production.py</li>
</ul>

<p>base.py has:  </p>

<pre><code>INSTALLED_APPS = (

    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes'
    ...
</code></pre>

<p>but I have some apps that I only want in my development environment, for example, <code>debug-toolbar</code>.  </p>

<p>I tried this in development.py:  </p>

<pre><code>INSTALLED_APPS += (
    'debug_toolbar',
)
</code></pre>

<p>But get the error: <code>NameError: name 'INSTALLED_APPS' is not defined</code></p>

<p>The settings files are connected like this:</p>

<p><code>__init__.py</code></p>

<pre><code>from .base import *

try:
    from .production import *
except:
    from .development import *
</code></pre>

<p>How can I differentiate the installed apps between my production/development environment?</p>