title: How to make email field unique in model User from contrib.auth in Django
body: <p>I need to patch the standard User model of <code>contrib.auth</code> by ensuring the email field entry is unique:</p>
  
  <pre><code>User._meta.fields[4].unique = True
  </code></pre>
  
  <p>Where is best place in code to do that?</p>
  
  <p>I want to avoid using the number <em>fields[4]</em>. It's better to user <em>fields['email']</em>, but <em>fields</em> is not dictionary, only list.</p>
  
  <p>Another idea may be to open a new ticket and upload a patch with new parameter inside <code>settings.py</code>: </p>
  
  <pre><code>AUTH_USER_EMAIL_UNIQUE = True
  </code></pre>
  
  <p>Any suggestions on the most correct way to achieve email address uniqueness in the Django User model?</p>