Update cartpole_gym_replay.py

cartpole_gym_replay.py

@@ -68,8 +68,8 @@ class DecisionTransformerGymDataset(datasets.GeneratorBasedBuilder):
         dones = np.load(f'{filepath}/dones.npy')
         for idx, value in enumerate(obs):
             yield idx, {
-                "observations": obs[i],
-                "actions": act[i],
-                "rewards": rew[i],
-                "dones": done[i],
+                "observations": obs[idx],
+                "actions": act[idx],
+                "rewards": rew[idx],
+                "dones": done[idx],
             }