arranged chartsview so keys are added to get_context_data as they are...

arranged chartsview so keys are added to get_context_data as they are calculated for greater clarity, not all at the end

bookshare/settings/views.py

@@ -31,27 +31,28 @@ class ChartsView(TemplateView):
         all_listings = Listing.objects.exclude(cancelled=True)
 
         all_isbns = [listing.isbn for listing in all_listings]
+        context['most_popular'] = Counter(all_isbns).most_common(20)
 
         grossing = []
+        # only want exchanged listings (not cancelled is assumed)
+        all_exchanged = Listing.objects.exclude(exchanged=False)
         # set to eliminate duplicates
         for isbn in set(all_isbns):
-            # only want exchanged listings (not cancelled is assumed)
-            listings = Listing.objects.exclude(exchanged=False).filter(isbn=isbn)
+            listings = all_exchanged.filter(isbn=isbn)
             # make list of all of that listing's final prices (assume no Nones)
             listing_winning_bids = [listing.final_price() for listing in listings]
             # add all those together
             listing_gross = sum(listing_winning_bids)
             # make a tuple of the isbn and gross and add it to the list
             grossing.append((isbn, listing_gross))
+        context['highest_grossing'] = sorted(grossing, key=lambda li: li[1],
+                                             reverse=True)[:20]
 
         total_proceeds = Listing.objects.aggregate(sum_price=Sum('winning_bid__price'))['sum_price']
+        context['total_proceeds'] = total_proceeds
 
-        context['most_popular'] = Counter(all_isbns).most_common(20)
         # sort by the second element of the tuple, descending
-        context['highest_grossing'] = sorted(grossing, key=lambda li: li[1],
-                                             reverse=True)[:20]
         context['total_listings'] = all_listings.count()
         context['total_bids'] = Bid.objects.count()
         context['total_students'] = Student.objects.count()
-        context['total_proceeds'] = total_proceeds
         return context