Initial commit

ttt/game.py

@@ -0,0 +1,61 @@
+class TTTGame:
+    "Models a tic-tac-toe game."
+
+    def get_initial_state(self):
+        "Returns the game's initial state."
+        return {
+            "board": ['-', '-', '-', '-', '-', '-', '-', '-', '-'],
+            "player_x": True,
+        }
+
+    def get_next_state(self, state, action):
+        """Given a state and an action, returns the resulting state.
+        In the resulting state, the current player's symbol has been placed 
+        in an empty board space, and it is the opposite player's turn.
+        """
+        new_board = state["board"].copy()
+        new_board[action] = 'X' if state["player_x"] else 'O'
+        return {
+            "board": new_board,
+            "player_x": not state["player_x"],
+        }
+
+    def get_actions(self, state):
+        "Returns a list of the indices of empty spaces"
+        return [index for index in range(9) if state["board"][index] == '-']
+
+    def is_over(self, state):
+        "Checks whether the game is over."
+        return self.board_is_full(state) or self.check_winner(state, 'X') or self.check_winner(state, 'O')
+
+    def get_reward(self, state):
+        """Determines the reward associated with reaching this state.
+        For tic-tac-toe, the two opponents each want a different game outcome. So 
+        we set the reward for X winning to 1 and the reward for O winning to -1.
+        All other states (unfinished games and games which ended in a draw) are worth 0.
+        """
+        if self.check_winner(state, 'X'):
+            return 1
+        elif self.check_winner(state, 'O'):
+            return -1
+        else:
+            return 0
+
+    def get_objective(self, state):
+        """Returns a player's objective, or a function describing what a player wants. 
+        This function should choose the best value from a list. In tic tac toe, the players
+        want opposite things, so we set X's objective to the built-in function `max`
+        (which chooses the largest number), and we set O's objective to the built-in function `min`.
+        """
+        return max if state["player_x"] else min
+
+    def board_is_full(self, state):
+        "Checks whether all the spaces in the board are occupied."
+        for space in state["board"]:
+            if space == '-':
+                return False
+        return True
+
+    def check_winner(self, state, symbol):
+        "Checks whether the player with `symbol` has won the game."
+        return False

ttt/player.py

@@ -0,0 +1,33 @@
+from click import Choice, prompt
+from strategy.random_strategy import RandomStrategy
+from ttt.game import TTTGame
+import random
+
+class TTTHumanPlayer:
+    "A human tic tac toe player."
+
+    def __init__(self, name):
+        "Sets up the player."
+        self.name = name
+        self.game = TTTGame()
+
+    def choose_action(self, state):
+        "Chooses an action by prompting the player for a choice."
+        actions = self.game.get_actions(state)
+        choices = Choice([str(action) for action in actions])
+        action = int(prompt("> ", type=choices, show_choices=False))
+        return action
+
+class TTTComputerPlayer:
+    "A computer tic tac toe player"
+
+    def __init__(self, name):
+        "Sets up the player."
+        self.name = name
+        self.strategy = RandomStrategy(TTTGame())
+
+    def choose_action(self, state):
+        "Chooses a random move from the moves available."
+        action = self.strategy.choose_action(state)
+        print(f"{self.name} chooses {action}.")
+        return action

ttt/view.py

@@ -0,0 +1,75 @@
+from ttt.game import TTTGame
+import click
+
+class TTTView:
+    "Handles user interaction with a tic-tac-toe game."
+    greeting = "Welcome to tic-tac-toe"
+    goodbye = "Well, that's a wrap."
+    divider = "---+---+---"
+    x_color = "red"
+    o_color = "blue"
+    option_color = "bright_black"
+
+    def __init__(self, playerX, playerO):
+        self.game = TTTGame()
+        self.players = {
+            "X": playerX, 
+            "O": playerO,
+        }
+
+    def greet(self):
+        "Starts a new game by greeting the players."
+        x_name = self.players['X'].name
+        o_name = self.players['O'].name
+        print(self.greeting)
+        print(f"{x_name} will play as X.")
+        print(f"{o_name} will play as O.")
+
+    def get_action(self, state):
+        "Shows the board and asks the current player for their choice of action."
+        self.print_board(state)
+        current_player_symbol = 'X' if state["player_x"] else 'O'
+        player = self.players[current_player_symbol]
+        print(f"{player.name}, it's your move.")
+        return player.choose_action(state)
+
+    def print_board(self, state):
+        "Prints the current board, showing indices of available spaces"
+        print(self.format_row(state, [0, 1, 2]))
+        print(self.divider)
+        print(self.format_row(state, [3, 4, 5]))
+        print(self.divider)
+        print(self.format_row(state, [6, 7, 8]))
+
+    def format_row(self, state, indices):
+        "Returns a string for one row in the board, like ' X | O | X '"
+        spaces = [self.format_value(state, i) for i in indices]
+        return f" {spaces[0]} | {spaces[1]} | {spaces[2]} "
+
+    def format_value(self, state, index):
+        """Formats the value for a single space on the board. 
+        If the game board already has a symbol in that space, formats that value for the Terminal.
+        If the space is empty, instead formats the index of the space. 
+        """
+        if state["board"][index] == 'X':
+            return click.style('X', fg=self.x_color)
+        elif state["board"][index] == 'O':
+            return click.style('O', fg=self.o_color)
+        else:
+            return click.style(index, fg=self.option_color)
+
+    def conclude(self, state):
+        """Says goodbye.
+        """
+        self.print_board(state)
+        if self.game.check_winner(state, 'X'):
+            winner = self.players['X']
+        elif self.game.check_winner(state, 'O'):
+            winner = self.players['O']
+        else:
+            winner = None
+        print(self.goodbye)
+        if winner:        
+            print(f"Congratulations to {winner.name}.")
+        else:
+            print("Nobody won this game.")