Now, I understand how ORM works... or not

accounting/templates/accounting/journal_bilan.jinja

@@ -14,13 +14,16 @@
         <thead>
         <tr>
             <td>{% trans %}Nature of operation{% endtrans %}</td>
-            <td>{% trans %}Amount{% endtrans %}</td>
+            <td>{% trans %}Sum{% endtrans %}</td>
         </tr>
         </thead>
-        <tbody></tr>
-        	<td>bla</td>
-        	<td>{{self.get_test()}}</td>
+        <tbody>
+            {% for key in bilan.keys() %}
                 <tr>
+                	<td>{{object.operations.get(accounting_type__code=key).accounting_type.label}}</td>
+                	<td>{{bilan[key]}}</td>
+                </tr>
+            {% endfor %}
         </tbody>
 
     </table>

accounting/templates/accounting/journal_details.jinja

@@ -22,6 +22,7 @@
     <p>{% trans %}Journal is closed, you can not create operation{% endtrans %}</p>
     {% else %}
     <p><a href="{{ url('accounting:op_new', j_id=object.id) }}">{% trans %}New operation{% endtrans %}</a></p>
+    <p><a href="{{ url('accounting:journal_bilan', j_id=object.id) }}">{% trans %}Journal Bilan{% endtrans %}</a></p>
     {% endif %}
     <table>
         <thead>

accounting/urls.py

@@ -26,6 +26,7 @@ urlpatterns = [
     url(r'^journal/create$', JournalCreateView.as_view(), name='journal_new'),
     url(r'^journal/(?P<j_id>[0-9]+)$', JournalDetailView.as_view(), name='journal_details'),
     url(r'^journal/(?P<j_id>[0-9]+)/edit$', JournalEditView.as_view(), name='journal_edit'),
+    url(r'^journal/(?P<j_id>[0-9]+)/bilan$', JournalBilanView.as_view(), name='journal_bilan'),
     # Operations
     url(r'^operation/create/(?P<j_id>[0-9]+)$', OperationCreateView.as_view(), name='op_new'),
     url(r'^operation/(?P<op_id>[0-9]+)$', OperationEditView.as_view(), name='op_edit'),

accounting/views.py

@@ -444,6 +444,35 @@ class OperationPDFView(CanViewMixin, DetailView):
         p.save()
         return response
 
+class JournalBilanView(CanViewMixin, DetailView):
+    """
+    Calculate a dictionary with operation code and sum of operations
+    """
+    model = GeneralJournal
+    pk_url_kwarg = "j_id"
+    template_name='accounting/journal_bilan.jinja'
+
+    def sum_by_code(self, code):
+        from decimal import Decimal
+        amount_sum = Decimal(0)
+        for amount in self.get_object().operations.filter(accounting_type__code=code).values('amount'):
+            amount_sum += amount['amount']
+        return amount_sum
+
+    def bilan(self):
+        bilan = {}
+        for el in AccountingType.objects.values('code').distinct():
+            bilan[el['code']] = self.sum_by_code(el['code'])
+        print(bilan)
+        return bilan
+
+    def get_context_data(self, **kwargs):
+        """ Add journal to the context """
+        kwargs = super(JournalBilanView, self).get_context_data(**kwargs)
+        kwargs['bilan'] = self.bilan()
+        return kwargs
+
+
 # Company views
 
 class CompanyListView(CanViewMixin, ListView):