修复路网更新缓慢bug

graph/topo_graph.py

@@ -114,6 +114,7 @@ class Topo():
         return self.work_area_distance_info
 
     def get_park_distance_info(self):
+        self.park_distance_info = []
         try:
             for item in session_postgre.query(WalkTimePark).all():
                 self.park_distance_info.append([[str(item.park_area_id), str(item.load_area_id)], item.park_load_lanes])