diff --git a/PathPlanning/BidirectionalAStar/bidirectional_a_star.py b/PathPlanning/BidirectionalAStar/bidirectional_a_star.py
index 37d14eab..4ffd3471 100644
--- a/PathPlanning/BidirectionalAStar/bidirectional_a_star.py
+++ b/PathPlanning/BidirectionalAStar/bidirectional_a_star.py
@@ -256,8 +256,8 @@ class BidirectionalAStarPlanner:
         print("ywidth:", self.ywidth)
 
         # obstacle map generation
-        self.obmap = [[False for i in range(self.ywidth)]
-                      for i in range(self.xwidth)]
+        self.obmap = [[False for _ in range(self.ywidth)]
+                      for _ in range(self.xwidth)]
         for ix in range(self.xwidth):
             x = self.calc_grid_position(ix, self.minx)
             for iy in range(self.ywidth):