title: Auto fill ForeignKey(User) with current signed in user in Django
body: <p>I am working on a Django project where users will enter data into CharFields, but to organize the data, each users post is marked with their own username. However, at the moment, users have to go through a list of registered users to find their username. As you can imagine this is both inconvenient. Is there any way I can have the Users field automatically dete which user is currently signed in and fill the field with that user's Username?</p>
  
  <p>Here is my models.py file:</p>
  
  <pre><code>class Post(models.Model):
      Post = models.CharField(max_length=7, unique=True)
      user = models.ForeignKey(User)
  </code></pre>
  
  <p>And here is my corresponding admin.py:</p>
  
  <pre><code>admin.site.register(StockTickerSymbol)
  </code></pre>
  
  <p>Is there any way I can set the ForeignKey(User) bit to default to the currently signed in user? Thank you.</p>