title: Exclude a package if DEBUG=True
body: <p>If <code>DEBUG=True</code>, I want to exclude the package <code>storages</code>. How would I do this?</p>
  
  <p>my settings.py:</p>
  
  <pre><code>if DEBUG:
      storages = ''
  
  INSTALLED_APPS = [
      ...
      'app',
      storages,
      ...
  ]
  </code></pre>