Fix mario_rl_tutorial.py

Author: alperenunlu

Diff for: intermediate_source/mario_rl_tutorial.py

@@ -43,7 +43,7 @@
 import numpy as np
 from pathlib import Path
 from collections import deque
-import random, datetime, os, copy
+import random, datetime, os
 
 # Gym is an OpenAI toolkit for RL
 import gym
@@ -424,20 +424,10 @@ def __init__(self, input_dim, output_dim):
         if w != 84:
             raise ValueError(f"Expecting input width: 84, got: {w}")
 
-        self.online = nn.Sequential(
-            nn.Conv2d(in_channels=c, out_channels=32, kernel_size=8, stride=4),
-            nn.ReLU(),
-            nn.Conv2d(in_channels=32, out_channels=64, kernel_size=4, stride=2),
-            nn.ReLU(),
-            nn.Conv2d(in_channels=64, out_channels=64, kernel_size=3, stride=1),
-            nn.ReLU(),
-            nn.Flatten(),
-            nn.Linear(3136, 512),
-            nn.ReLU(),
-            nn.Linear(512, output_dim),
-        )
+        self.online = self.__build_cnn(c, output_dim)
 
-        self.target = copy.deepcopy(self.online)
+        self.target = self.__build_cnn(c, output_dim)
+        self.target.load_state_dict(self.online.state_dict())
 
         # Q_target parameters are frozen.
         for p in self.target.parameters():
@@ -449,6 +439,20 @@ def forward(self, input, model):
         elif model == "target":
             return self.target(input)
 
+    def __build_cnn(self, c, output_dim):
+        return nn.Sequential(
+            nn.Conv2d(in_channels=c, out_channels=32, kernel_size=8, stride=4),
+            nn.ReLU(),
+            nn.Conv2d(in_channels=32, out_channels=64, kernel_size=4, stride=2),
+            nn.ReLU(),
+            nn.Conv2d(in_channels=64, out_channels=64, kernel_size=3, stride=1),
+            nn.ReLU(),
+            nn.Flatten(),
+            nn.Linear(3136, 512),
+            nn.ReLU(),
+            nn.Linear(512, output_dim),
+        )
+
 
 ######################################################################
 # TD Estimate & TD Target