Fixed error of run_policy.py with python 3.6

code/run_policy.py

@@ -1,13 +1,14 @@
 """
 
-Code to load a policy and generate rollout data. Adapted from https://github.com/berkeleydeeprlcourse. 
+Code to load a policy and generate rollout data. Adapted from https://github.com/berkeleydeeprlcourse.
 Example usage:
     python run_policy.py ../trained_policies/Humanoid-v1/policy_reward_11600/lin_policy_plus.npz Humanoid-v1 --render \
             --num_rollouts 20
 """
 import numpy as np
 import gym
 
+
 def main():
     import argparse
     parser = argparse.ArgumentParser()
@@ -20,13 +21,13 @@ def main():
 
     print('loading and building expert policy')
     lin_policy = np.load(args.expert_policy_file)
-    lin_policy = lin_policy.items()[0][1]
-    
+    lin_policy = lin_policy[lin_policy.files[0]]
+
     M = lin_policy[0]
-    # mean and std of state vectors estimated online by ARS. 
+    # mean and std of state vectors estimated online by ARS.
     mean = lin_policy[1]
     std = lin_policy[2]
-        
+
     env = gym.make(args.envname)
 
     returns = []
@@ -42,8 +43,8 @@ def main():
             action = np.dot(M, (obs - mean)/std)
             observations.append(obs)
             actions.append(action)
-            
-            
+
+
             obs, r, done, _ = env.step(action)
             totalr += r
             steps += 1
@@ -57,6 +58,6 @@ def main():
     print('returns', returns)
     print('mean return', np.mean(returns))
     print('std of return', np.std(returns))
-    
+
 if __name__ == '__main__':
     main()