title: Dynamic choices field in Django Models
body: <p>My models.py:</p>
  
  <pre><code>SHOP1_CHOICES = (
      ('Food Court', 'Food Court'),
      ('KFC', 'KFC'),
  
  )
  
  SHOP2_CHOICES = (
      ('Sports Arena', 'Sports Arena'),
      ('Disco D', 'Disco D'),
  
  )
  
  SHOP3_CHOICES = (
      ('Bowling Arena', 'Bowling Arena'),
      ('Cinemax', 'Cinemax'),
  
  )
  
  class Feed(models.Model):
    gender = models.CharField(max_length=5, choices=GENDER_CHOICES, default='girl')
    name =models.CharField(max_length=25)
    shop=models.CharField(max_length=20)
    location=models.CharField(max_length=25, choices=SHOP1_CHOICES)
  </code></pre>
  
  <p>Here if <code>Feed.shop == 'shop1'</code> I want to load <code>SHOP1_CHOICES</code> on <code>Feed.location</code>. Currently irrespective of what shop, it just displays the <code>SHOP1_CHOICES</code> (no surprise).How can I implement it? I am stuck, please help.</p>