chore: remove unused method str_to_bool()

main.py

@@ -83,16 +83,6 @@ def play(context: GameContext, first: bool, mcts: bool = False):
      save_path=connect4_path
 )
 
-def str2bool(v: str) -> bool:
-    if isinstance(v, bool):
-        return v
-    if v.lower() in ('yes', 'true', 't', 'y', '1'):
-        return True
-    elif v.lower() in ('no', 'false', 'f', 'n', '0'):
-        return False
-    else:
-        raise ArgumentTypeError('Boolean value expected.')
-
 parser: ArgumentParser = ArgumentParser(description='Control the execution of the AlphaZero game playing system.')
 parser.add_argument('--test_overfit', action='store_true', help='Test overfitting on Connect Four.')
 parser.add_argument('--train_ttt', action='store_true', help='Train AlphaZero on Tic Tac Toe.')

src/alphazero/agents/alphazero_play_agent.py

@@ -11,7 +11,7 @@ class AlphaZero:
     def __init__(self, context: GameContext):
         self.context = context
         self.shape = [1] + context.game.observation_tensor_shape()
-        self.c = 1.41 # Exploration constant
+        self.c = 4. # Exploration constant
 
     def run_simulation(self, state, num_simulations=800): # Num-simulations 800 is good for tic-tac-toe
         """
@@ -57,7 +57,6 @@ def alphazero_self_play(context: GameContext, num_simulations=800):
 
     while (not state.is_terminal()):
         action = alphazero.run_simulation(state, num_simulations)
-        print("best action\t", action, "\n")
         state.apply_action(action)
         print(state)