title: Django: How to amend a model being created?
body: <pre><code>class Timeline(models.Model):
      name = models.CharField(blank=False, max_length=256)
      # ...
  
  class User(models.Model):
      main_timeline = models.OneToOneField('Timeline', related_name='holder_user', null=False)
      # ...
  </code></pre>
  
  <p>When creating a user, I want a new timeline to be created automatically and assigned to <code>main_timeline</code> field.</p>
  
  <p>So far, the best solution I have is not to use <code>User.objects.create()</code> directly but instead wrap it into another method.</p>
  
  <p>Are there other solutions?</p>