Upd program syntax

app.py

@@ -174,8 +174,7 @@ def astar(start, goal, occ):
     N8 = [(-1,-1), (-1,0), (-1,1), (0,-1), (0,1), (1,-1), (1,0), (1,1)]
     openq = [(0, start)]
     g = {start: 0}
-    came = {}
-    visited = set()
+    came = {}; visited = set() # Flag visited for path optimization
     H, W = occ.shape
     while openq:
         _, cur = heapq.heappop(openq)
@@ -210,7 +209,7 @@ def astar(start, goal, occ):
 def knn_path(start, targets, occ):
     todo = targets[:]; path=[]
     cur  = tuple(start)
-    reachable = []; unreachable = []
+    reachable = []; unreachable = [] # flag unreachable apart
     for t in todo:
         seg = astar(cur, tuple(t), occ)
         if seg:
@@ -484,6 +483,7 @@ def _pipeline(uid,img_path):
     robot = Robot(SPRITE)
     # Robot will be spawn on the closest movable mask to top-left
     robot.pos = [spawn_x, spawn_y]
+    # Unreachable targets flagged
     path, unreachable_targets = knn_path(robot.pos, centres, movable_mask)
     objs = [{"pos": p, "col": False, "unreachable": False} for p in centres if p not in unreachable_targets]
     objs += [{"pos": p, "col": False, "unreachable": True} for p in unreachable_targets]