Apply pylint rules on selector.py.

modules/selector.py

@@ -79,9 +79,10 @@ class SelectorActiveItems(Selector):
         query = Selector.query(self, table)
 
         if self._period_start and self._period_end:
-            q = table.start_date <= self._period_end
-            q = (q) & ((table.end_date == None) | (table.end_date >= self._period_start))
-            query = (query) & (q)
+            q1 = table.start_date <= self._period_end
+            q2 = table.end_date is None
+            q3 = table.end_date >= self._period_start
+            query &= (q1) & (q2 | q3)
 
         return query