Initial version of lab

ttt_game.py

@@ -0,0 +1,45 @@
+
+class TTTGame:
+    """Models a tic-tac-toe game.
+    """
+
+    def __init__(self, playerX, playerO):
+        self.board = [None] * 9
+        self.turn_index = 0
+        self.players = {
+            'X': playerX,
+            'O': playerO,
+        }
+
+    def play_move(self, move):
+        if not self.is_valid_move(move):
+            raise ValueError(f"Illegal move {move} with board {self.board}.")
+        self.board[move] = self.get_current_player_symbol()
+        self.turn_index += 1
+
+    def get_valid_moves(self):
+        "Returns a list of the indices of empty spaces"
+        return [index for index in range(9) if self.board[index] is None]
+
+    def is_valid_move(self, move):
+        "Checks whether a move is valid."
+        return move in self.get_valid_moves()
+
+    def get_current_player_symbol(self):
+        "Returns the symbol of the current player"
+        if self.turn_index % 2 == 0:
+            return 'X'
+        else:
+            return 'O'
+
+    def get_current_player(self):
+        "Returns the symbol of the current player and the current player"
+        return self.players[self.get_current_player_symbol()]
+        
+    def is_over(self):
+        "Checks whether the game is over."
+        return self.check_winner('X') or self.check_winner('O')
+
+    def check_winner(self, symbol):
+        "Checks whether the player with `symbol` has won the game."
+        return False