title: Django: Queryset not saving changes to value?
body: <p>Here, <code>result</code> is a Queryset. I am going through it and updating the value for it's <code>price</code> attribute to match what I get from the <code>price_map.price</code> value in my second query to <code>Product.objects</code>. </p>
  
  <p>This works and updates the prices accordingly. Until it goes into the <code>.order_by</code> method. Then, all of the values of <code>price</code> return to what they originally were.</p>
  
  <pre><code>if sort_by in valid_sorts:
              for item in result:
                  retrieved_item = Product.objects.get(name=item.name).get_pricing_info(self.request.session.get('visitors_country'))
                  if retrieved_item['price_map'] is None:
                      print 'we got a none here! ', item.name
                  else:
                      item.price = retrieved_item['price_map'].price
  
              if sort_by == 'highlow':
                  result = result.order_by('-price')
              elif sort_by == 'lowhigh':
                  result = result.order_by('price')
              elif sort_by == 'newest':
                  result = result.order_by('-date','-price')
              elif sort_by == 'relevancy':
                  pass
  </code></pre>
  
  <p>If I add in some print statements for just before and just after the <code>.order_by</code> call, here is the output I get:</p>
  
  <pre><code>Just before the order!
  79.99
  119.99
  99.99
  69.99
  119.99
  89.99
  69.99
  69.99
  99.99
  44.99
  599.99
  599.99
  69.99
  69.99
  69.99
  69.99
  249.99
  799.99
  119.99
  139.99
  199.99
  249.99
  139.99
  149.99
  139.99
  69.99
  139.99
  199.99
  69.99
  29.99
  0.0
  139.99
  34.99
  54.99
  119.99
  149.99
  69.99
  69.99
  89.99
  119.99
  119.99
  149.99
  149.99
  1699.99
  69.99
  249.99
  39.99
  39.99
  39.99
  599.99
  999.99
  199.99
  49.99
  119.99
  119.99
  249.99
  99.99
  99.99
  199.99
  69.99
  99.99
  39.99
  169.99
  this is the high low sort!
  1499.99
  599.99
  599.99
  399.99
  349.99
  299.99
  249.99
  209.99
  199.99
  199.99
  179.99
  159.99
  159.99
  129.99
  129.99
  119.99
  119.99
  119.99
  119.99
  119.99
  99.99
  99.99
  89.99
  89.99
  89.99
  69.99
  69.99
  69.99
  69.99
  59.99
  59.99
  49.99
  49.99
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  0.0
  </code></pre>
  
  <p>Stack trace for the issue when I try to save the item after changing the price value in the for loop:</p>
  
  <pre><code>Traceback (most recent call last):
    File "/home/user/.virtualenvs/rf/local/lib/python2.7/site-packages/django/core/handlers/exception.py", line 39, in inner
      response = get_response(request)
    File "/home/user/.virtualenvs/rf/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 249, in _legacy_get_response
      response = self._get_response(request)
    File "/home/user/.virtualenvs/rf/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 187, in _get_response
      response = self.process_exception_by_middleware(e, request)
    File "/home/user/.virtualenvs/rf/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 185, in _get_response
      response = wrapped_callback(request, *callback_args, **callback_kwargs)
    File "/home/user/.virtualenvs/rf/local/lib/python2.7/site-packages/django/views/generic/base.py", line 68, in view
      return self.dispatch(request, *args, **kwargs)
    File "/home/user/.virtualenvs/rf/local/lib/python2.7/site-packages/django/views/generic/base.py", line 88, in dispatch
      return handler(request, *args, **kwargs)
    File "/home/user/.virtualenvs/rf/local/lib/python2.7/site-packages/haystack/generic_views.py", line 120, in get
      form = self.get_form(form_class)
    File "/home/user/.virtualenvs/rf/local/lib/python2.7/site-packages/django/views/generic/edit.py", line 45, in get_form
      return form_class(**self.get_form_kwargs())
    File "/home/user/.virtualenvs/rf/local/lib/python2.7/site-packages/haystack/generic_views.py", line 94, in get_form_kwargs
      kwargs = super(FacetedSearchMixin, self).get_form_kwargs()
    File "/home/user/.virtualenvs/rf/local/lib/python2.7/site-packages/haystack/generic_views.py", line 65, in get_form_kwargs
      kwargs.update({'searchqueryset': self.get_queryset()})
    File "/home/user/Documents/sandbox/opt/rock/ro/rf/products/views.py", line 344, in get_queryset
      item.save()
  TypeError: 'NoneType' object is not callable
  </code></pre>