title: Django - catch exception
body: <p>Looking at this code:</p>
  <pre><code>try:
     ...  # do something
  except:
     raise Exception('XYZ has gone wrong...')
  </code></pre>
  <p>Even with <code>DEBUG=True</code>, I don't want this <code>raise Exception</code> to give that yellow page, but it does.</p>
  <p>I want to handle the exception by redirecting users to an error page or shows the error (give a CSS error message on the top of the page...)</p>
  <p>How do I handle that? If I simply raise it, I will get yellow debug page (again, I don't want certain exceptions to stop the site from functioning by showing the debug page when DEBUG=True).</p>
  <p>How do I handle these exceptions in views.py?</p>