title: How to iterate over every foreign key in a model?
body: <p>If I have a model like the following:</p>
  
  <pre><code>class Keyword(models.Model):
      model1 = models.ForeignKey(Model1, null=True, blank=True, default=None)
      model2 = models.ForeignKey(Model2, null=True, blank=True, default=None)
      model3 = models.ForeignKey(Model3, null=True, blank=True, default=None)
      model4 = models.ForeignKey(Model4, null=True, blank=True, default=None)      
      not_foreign_key = models.CharField(max_length=10, null=True, blank=True)
  </code></pre>
  
  <p>How can I iterate over each foreign key?</p>
  
  <p>I'm imagining some sort of for loop like this (pseudocode):</p>
  
  <pre><code>for each foreign key in Keyword:
      do something with the foreign key
  </code></pre>
  
  <p>Thank you for your help.</p>