commit dd3eb11ea827ad1aaaa79c067455131c15764075
Author: Dominik Brunmeir <dominik.brunmeir@dwh.at>
Date:   Fri Jul 22 13:08:35 2022 +0200

    initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..82f4808
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,25 @@
+# ---> macOS
+.DS_Store
+.AppleDouble
+.LSOverride
+# Icon must end with two \r
+Icon
+# Thumbnails
+._*
+__pycache__
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+run_old.py
+.idea
+venv
diff --git a/Player.py b/Player.py
new file mode 100644
index 0000000..ea1bcbe
--- /dev/null
+++ b/Player.py
@@ -0,0 +1,136 @@
+from abc import ABC, abstractmethod
+
+import numpy as np
+import pickle
+
+'''
+    Class defines Computer-Player
+'''
+
+
+class Player(ABC):
+
+    def __init__(self, name: str):
+        self.name = name
+
+    @abstractmethod
+    def get_hash(self, board: np.array):
+        pass
+
+    @abstractmethod
+    def choose_action(self, positions: list, current_board: np.array = None, symbol: int = -1) -> tuple:
+        pass
+
+    @abstractmethod
+    def feed_reward(self, reward: float) -> None:
+        pass
+
+    @abstractmethod
+    def reset(self) -> None:
+        pass
+
+    @abstractmethod
+    def add_state(self, state: np.array) -> None:
+        pass
+
+
+class ComputerPlayer(Player):
+    def __init__(self, name: str, board_cols: int, board_rows: int, exp_rate: float = 0.3):
+        super().__init__(name)
+        self.states = []
+        self.lr = 0.2
+        self.exp_rate = exp_rate
+        self.decay_gamma = 0.9
+        self.states_value = {}
+        self.board_cols = board_cols
+        self.board_rows = board_rows
+
+    '''
+        get Board hash
+    '''
+
+    def get_hash(self, board: np.array) -> str:
+        board_hash = str(board.reshape(self.board_cols * self.board_rows))
+        return board_hash
+
+    '''
+        get best action for current state
+    '''
+
+    def choose_action(self, positions: list, current_board: np.array = None, symbol: int = -1) -> tuple:
+        if np.random.uniform(0, 1) <= self.exp_rate:
+            # take random action
+            idx = np.random.choice(len(positions))
+            action = positions[idx]
+        else:
+            value_max = -999
+            for p in positions:
+                next_board = current_board.copy()
+                next_board[p] = symbol
+                next_board_hash = self.get_hash(next_board)
+                value = 0 if self.states_value.get(next_board_hash) is None else self.states_value.get(next_board_hash)
+                if value >= value_max:
+                    value_max = value
+                    action = p
+        return action
+
+    def add_state(self, state: np.array) -> None:
+        self.states.append(state)
+
+    '''
+        at the end of game, backpropagate and update states value
+    '''
+
+    def feed_reward(self, reward: float) -> None:
+        for st in reversed(self.states):
+            if self.states_value.get(st) is None:
+                self.states_value[st] = 0
+            # bellman equation
+            self.states_value[st] += self.lr * (self.decay_gamma * reward - self.states_value[st])
+            reward = self.states_value[st]
+
+    def reset(self) -> None:
+        self.states = []
+
+    def save_policy(self) -> None:
+        fw = open('policy_' + str(self.name), 'wb')
+        pickle.dump(self.states_value, fw)
+        fw.close()
+
+    def load_policy(self, file) -> None:
+        fr = open(file, 'rb')
+        self.states_value = pickle.load(fr)
+        fr.close()
+
+
+'''
+    Class for Human-Player
+'''
+
+
+class HumanPlayer(Player):
+
+    def __init__(self, name):
+        super().__init__(name)
+
+    def choose_action(self, positions: list, current_board: np.array = None, symbol: int = -1) -> tuple:
+        while True:
+            row = int(input("Input your action row:"))
+            col = int(input("Input your action col:"))
+            action = (row, col)
+            if action in positions:
+                return action
+
+    # append a hash state
+    def add_state(self, state) -> None:
+        pass
+
+    # at the end of game, backpropagate and update states value
+    def feed_reward(self, reward: float) -> None:
+        pass
+
+    def get_hash(self, board: np.array):
+        pass
+
+    def reset(self) -> None:
+        pass
diff --git a/State.py b/State.py
new file mode 100644
index 0000000..b4848f6
--- /dev/null
+++ b/State.py
@@ -0,0 +1,215 @@
+import numpy as np
+
+from Player import Player
+
+'''
+    Class defines Boardstates, rules for winning and distinguish between pure computer game and game against a human
+'''
+
+
+class State:
+    def __init__(self, p1: Player, p2: Player, board_rows: int, board_cols: int):
+        self.board = np.zeros((board_rows, board_cols))
+        self.p1 = p1
+        self.p2 = p2
+        self.isEnd = False
+        self.board_hash = None
+        self.player_symbol = 1
+        self.board_cols = board_cols
+        self.board_rows = board_rows
+
+    '''
+        Get unique hash of current board state
+    '''
+
+    def get_hash(self) -> str:
+        self.board_hash = str(self.board.reshape(self.board_cols * self.board_rows))
+        return self.board_hash
+
+    '''
+        Define winning rules
+    '''
+
+    def winner(self):
+        # 3 in a row
+        for i in range(self.board_rows):
+            if sum(self.board[i, :]) == 3:
+                self.isEnd = True
+                return 1
+            if sum(self.board[i, :]) == -3:
+                self.isEnd = True
+                return -1
+        # 3 in a column
+        for i in range(self.board_cols):
+            if sum(self.board[:, i]) == 3:
+                self.isEnd = True
+                return 1
+            if sum(self.board[:, i]) == -3:
+                self.isEnd = True
+                return -1
+        # diagonal
+        diag_sum1 = sum([self.board[i, i] for i in range(self.board_cols)])
+        diag_sum2 = sum([self.board[i, self.board_cols - i - 1] for i in range(self.board_cols)])
+        diag_sum = max(abs(diag_sum1), abs(diag_sum2))
+        if diag_sum == 3:
+            self.isEnd = True
+            if diag_sum1 == 3 or diag_sum2 == 3:
+                return 1
+            else:
+                return -1
+
+        # tie
+        # no available positions
+        if len(self.available_positions()) == 0:
+            self.isEnd = True
+            return 0
+        # not end
+        self.isEnd = False
+        return None
+
+    '''
+        Returns all available positions in current state
+    '''
+
+    def available_positions(self) -> list:
+        positions = []
+        for i in range(self.board_rows):
+            for j in range(self.board_cols):
+                if self.board[i, j] == 0:
+                    positions.append((i, j))  # need to be tuple
+        return positions
+
+    '''
+        Set token on a position and switch to another player
+    '''
+
+    def update_state(self, position) -> None:
+        self.board[position] = self.player_symbol
+        self.player_symbol = -1 if self.player_symbol == 1 else 1
+
+    '''
+        If game ends, backpropagate reward
+    '''
+
+    def give_reward(self) -> None:
+        result = self.winner()
+        # P1 won
+        if result == 1:
+            self.p1.feed_reward(1)
+            self.p2.feed_reward(0)
+        # P2 won
+        elif result == -1:
+            self.p1.feed_reward(0)
+            self.p2.feed_reward(1)
+        # Tie
+        else:
+            self.p1.feed_reward(0.1)
+            self.p2.feed_reward(0.5)
+
+    '''
+        Reset Board to Startposition
+    '''
+
+    def reset(self) -> None:
+        self.board = np.zeros((self.board_rows, self.board_cols))
+        self.board_hash = None
+        self.isEnd = False
+        self.player_symbol = 1
+
+    '''
+        Game with 2 Computer
+    '''
+
+    def play(self, rounds=100) -> None:
+        for i in range(rounds):
+            if i % 1000 == 0:
+                print("Rounds {}".format(i))
+            while not self.isEnd:
+                # Player 1
+                positions = self.available_positions()
+                p1_action = self.p1.choose_action(positions, self.board, self.player_symbol)
+                self.update_state(p1_action)
+                board_hash = self.get_hash()
+                self.p1.add_state(board_hash)
+
+                # Does P1 won or is it a tie?
+                win = self.winner()
+                if win is not None:
+                    self.give_reward()
+                    self.p1.reset()
+                    self.p2.reset()
+                    self.reset()
+                    break
+
+                else:
+                    # Player 2
+                    positions = self.available_positions()
+                    p2_action = self.p2.choose_action(positions, self.board, self.player_symbol)
+                    self.update_state(p2_action)
+                    board_hash = self.get_hash()
+                    self.p2.add_state(board_hash)
+
+                    # Does P2 won or is it a tie?
+                    win = self.winner()
+                    if win is not None:
+                        self.give_reward()
+                        self.p1.reset()
+                        self.p2.reset()
+                        self.reset()
+                        break
+
+    # Game with a human
+    def play2(self) -> None:
+        while not self.isEnd:
+            # Player 1
+            positions = self.available_positions()
+            p1_action = self.p1.choose_action(positions, self.board, self.player_symbol)
+            self.update_state(p1_action)
+            self.show_board()
+
+            # Does P1 won or is it a tie?
+            win = self.winner()
+            if win is not None:
+                if win == 1:
+                    print(self.p1.name, "wins!")
+                else:
+                    print("tie!")
+                self.reset()
+                break
+
+            else:
+                # Player 2 (Human)
+                positions = self.available_positions()
+                p2_action = self.p2.choose_action(positions)
+                self.update_state(p2_action)
+                self.show_board()
+
+                # Does P2 won or is it a tie?
+                win = self.winner()
+                if win is not None:
+                    if win == -1:
+                        print(self.p2.name, "wins!")
+                    else:
+                        print("tie!")
+                    self.reset()
+                    break
+
+    '''
+        Prints current state of Board
+    '''
+
+    def show_board(self):
+        # P1: x  P2: o
+        for i in range(0, self.board_rows):
+            print('-------------')
+            out = '| '
+            for j in range(0, self.board_cols):
+                if self.board[i, j] == 1:
+                    token = 'x'
+                if self.board[i, j] == -1:
+                    token = 'o'
+                if self.board[i, j] == 0:
+                    token = ' '
+                out += token + ' | '
+            print(out)
+        print('-------------')
diff --git a/main.py b/main.py
new file mode 100644
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--- /dev/null
+++ b/main.py
@@ -0,0 +1,29 @@
+from Player import ComputerPlayer, HumanPlayer
+from State import State
+
+BOARD_ROWS = 3
+BOARD_COLS = 3
+
+
+def tic_tac_toe():
+    # train with 2 computer player
+    p1 = ComputerPlayer("p1", board_cols=BOARD_COLS, board_rows=BOARD_ROWS)
+    p2 = ComputerPlayer("p2", board_cols=BOARD_COLS, board_rows=BOARD_ROWS)
+
+    st = State(p1, p2, board_cols=BOARD_COLS, board_rows=BOARD_ROWS)
+    print("training...")
+    st.play(50000)
+    p1.save_policy()
+
+    # play with human
+    p1 = ComputerPlayer("computer", board_cols=BOARD_COLS, board_rows=BOARD_ROWS, exp_rate=0)
+    p1.load_policy("policy_p1")
+
+    p2 = HumanPlayer("human")
+
+    st = State(p1, p2, board_cols=BOARD_COLS, board_rows=BOARD_ROWS)
+    st.play2()
+
+
+if __name__ == "__main__":
+    tic_tac_toe()
diff --git a/readme.md b/readme.md
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--- /dev/null
+++ b/readme.md
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+# Tic Tac Toe
+
+A simple game of tic tac toe
+
+Q-Learning example as part of the asim reinforcement learning tutorial.
+the agent (player) learns not to lose the game, given sufficiently long training period.
+