Enable multiple gold objects

examples/wumpus-usage.py

@@ -70,7 +70,7 @@ WUMPUS_WORLD = '''
         "pits": [[4, 0], [3, 1], [2, 2], [6, 2], [4, 4], [3, 5], [4, 6], [5, 6]],
         "wumpuses": [[1, 2]],
         "exits": [[0, 0]],
-        "golds": [[6, 3]],
+        "golds": [[6, 3], [3, 3]],
         "blocks": []
     }
 '''

wumpus/wumpus.py

@@ -91,7 +91,7 @@ class Hunter(Agent):
         self._arrow: bool = True
         self._done: bool = False
         self._bump: bool = False
-        self._has_gold: bool = False
+        self._has_gold: int = 0
 
     @property
     def world(self) -> 'WumpusWorld':
@@ -214,14 +214,13 @@ class Hunter(Agent):
             reward -= 1
             gold = self.world.isGold(self.location)
             if gold:
-                self._has_gold = True
+                self._has_gold += 1
                 self.world.removeObject(gold)
         elif action == self.Actions.CLIMB:
             reward -= 1
             if self.world.isExit(self.location):
                 self._done = True
-                if self._has_gold:
-                    reward += 1000
+                reward += 1000 * self._has_gold
         else:
             raise ValueError('Unrecognised action {}'.format(action))