Navigate through different maps while climbing ladders

squirrelbattle/interfaces.py

@@ -140,12 +140,15 @@ class Map:
         Put randomly {count} entities on the map, where it is available.
         """
         for ignored in range(count):
-            y, x = 0, 0
             while True:
                 y, x = randint(0, self.height - 1), randint(0, self.width - 1)
-                tile = self.tiles[y][x]
-                if tile.can_walk():
-                    break
+                try:
+                    tile = self.tiles[y][x]
+                except Exception as e:
+                    raise Exception(y, x, len(self.tiles))
+                else:
+                    if tile.can_walk():
+                        break
             entity = choice(Entity.get_all_entity_classes())()
             entity.move(y, x)
             self.add_entity(entity)