title: How do I set default field value to value of other field in a Django model?
body: <p>If I have the following model in django;</p>
  
  <pre><code>class MyModel(models.Model):  
      name = models.CharField(max_length=50)
      fullname = models.CharField(max_length=100,default=name)
  </code></pre>
  
  <p>How do I make the fullname field default to name? As it is right now, the fullname defaults to the string representation of the name CharField.</p>
  
  <p>Example: </p>
  
  <pre><code>new MyModel(name='joel')
  </code></pre>
  
  <p>would yield 'joel' as both name and fullname, whereas </p>
  
  <pre><code>new MyModel(name='joel',fullname='joel karlsson')
  </code></pre>
  
  <p>would yield different name and fullname.</p>