title: Django AssertionError
body: <pre><code>    AssertionError at /api/purchases/person/
  
      It is redundant to specify `source='name'` on field 'Field' in
   serializer 'PurchaseSerializer', because it is the same as the field name. 
  Remove the `source` keyword argument.
  </code></pre>
  
  <p>I assume it's referring to this code since I haven't use 'source' anywhere else:</p>
  
  <pre><code>class PurchaseSerializer(serializers.HyperlinkedModelSerializer):
      name = serializers.Field(source='name')
  
      class Meta:
          model = Purchase
          fields = ['name']
  </code></pre>
  
  <p>I'm trying to be able to filter purchases by "person" so I could only see their purchases BUT for some reason when I type a person that exists in the database it comes up with an Assertion error like above. If I type a person that does NOT exist in the database it throws no errors but returns an empty JSON. This should be vice versa but not sure why this isn't working.</p>
  
  <p>Models.py</p>
  
  <pre><code>class Purchase(models.Model):
          name = models.CharField(max_length=255)
  </code></pre>
  
  <p>Urls.py</p>
  
  <pre><code>url(r'^api/purchases/(?P&lt;username&gt;.+)/$', views.PurchaseList.as_view()),
  </code></pre>
  
  <p>Views.py</p>
  
  <pre><code>class PurchaseList(generics.ListAPIView):
      serializer_class = PurchaseSerializer
  
      def get_queryset(self):
          """
          This view should return a list of all the purchases for
          the user as determined by the username portion of the URL.
          """
          username = self.kwargs['username']
          return Purchase.objects.filter(name=username)
  </code></pre>