Update mario_rl_tutorial.py (#2381)

* Update mario_rl_tutorial.py
Fixes #1620
---------
Co-authored-by: Vincent Moens <vincentmoens@gmail.com>
Co-authored-by: Svetlana Karslioglu <svekars@fb.com>

intermediate_source/mario_rl_tutorial.py

@@ -53,6 +53,8 @@
 # Super Mario environment for OpenAI Gym
 import gym_super_mario_bros
 
+from tensordict import TensorDict
+from torchrl.data import TensorDictReplayBuffer, LazyMemmapStorage
 
 ######################################################################
 # RL Definitions
@@ -348,7 +350,7 @@ def act(self, state):
 class Mario(Mario):  # subclassing for continuity
     def __init__(self, state_dim, action_dim, save_dir):
         super().__init__(state_dim, action_dim, save_dir)
-        self.memory = deque(maxlen=100000)
+        self.memory = TensorDictReplayBuffer(storage=LazyMemmapStorage(100000))
         self.batch_size = 32
 
     def cache(self, state, next_state, action, reward, done):
@@ -373,14 +375,15 @@ def first_if_tuple(x):
         reward = torch.tensor([reward], device=self.device)
         done = torch.tensor([done], device=self.device)
 
-        self.memory.append((state, next_state, action, reward, done,))
+        # self.memory.append((state, next_state, action, reward, done,))
+        self.memory.add(TensorDict({"state": state, "next_state": next_state, "action": action, "reward": reward, "done": done}, batch_size=[]))
 
     def recall(self):
         """
         Retrieve a batch of experiences from memory
         """
-        batch = random.sample(self.memory, self.batch_size)
-        state, next_state, action, reward, done = map(torch.stack, zip(*batch))
+        batch = self.memory.sample(self.batch_size)
+        state, next_state, action, reward, done = (batch.get(key) for key in ("state", "next_state", "action", "reward", "done"))
         return state, next_state, action.squeeze(), reward.squeeze(), done.squeeze()