[fix] timedelta & read_group errors

.gitignore

+.*
+*.pyc
+!.gitignore

models/enercoop_operation.py

@@ -169,7 +169,7 @@ class EnercoopOperation(models.Model):
             scale = 'day'
             return scale
         else:
-            delta = date_end - date_start
+            delta = (date_end - date_start).days
             if delta <= 7:
                 scale = 'week'
             elif delta <= 31:
@@ -410,7 +410,7 @@ class EnercoopOperation(models.Model):
             [('enercoop_operation_id', 'in', self.ids),
              ('date_slot', '>=', date_start),
              ('date_slot', '<', date_end)],
-            ['power', 'enercoop_operation_id', 'date_slot', 'year'],
+            ['power', 'enercoop_operation_id', 'date_slot'],
             ['comp_data_type', type_date], orderby='comp_data_type, date_slot ASC', lazy=False)
 
         # Get the date for the abscissa axis