title: How to fix KeyError when accessing 'DJANGO_DEBUG' variable
body: <p>I am getting following error while executing migrate command: <code>python manage.py migrate</code>.</p>
  
  <pre><code>File "/Users/Jhon/djangowww/project/app/blog/settings.py", line 29, in &lt;module&gt;
  DEBUG = os.environ['DJANGO_DEBUG'] == 'True'
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/os.py", line 725, in __getitem__
  raise KeyError(key) from None
  KeyError: 'DJANGO_DEBUG'
  </code></pre>
  
  <p>How can recover from this issue?</p>