class Environment(object):
'''
Class that serves as an interface that Players use to interact with the Board
Environment manages which player is currently active, manages when the game is over,
manages hwo the board state is represented to players, etc.
'''
def __init__(self, board_w=7, board_h=7, num_to_win=4):
self.b = Board(board_w, board_h, num_to_win=num_to_win)
self.cur_player = Cell.RED
self.num_actions = board_w
self.is_game_over = False
self.num_moves: int = 0
self.last_move = None # last move in game (col, row)
self.history = [
] # history will be a list of tuples (state, action, reward)
def get_num_cells(self) -> int:
return self.b.get_num_cells()
def reset(self) -> None:
h, w, ntw = self.b.height, self.b.width, self.b.num_to_win
self.b = Board(width=w, height=h, num_to_win=ntw)
self.cur_player = Cell.RED
self.is_game_over = False
self.num_moves = 0
self.last_move = None
self.history = []
def _actually_take_action(self, col: int) -> float:
'''
Moves the current player into the column specified by 'col'
Returns the score of the last move: -1 if illegal, 1 if winning, 0 otherwise
'''
state = self.get_state()
try:
row = self.b.move(col, self.cur_player)
except ValueError: # illegal moves cause game over
self.is_game_over = True
return -1
self.last_move = (col, row)
# change current player
self.cur_player = Cell.RED if self.cur_player == Cell.BLACK else Cell.BLACK
self.num_moves += 1
# check if any legal moves remain
if self.num_moves >= self.get_num_cells():
self.is_game_over = True
if self.b.check_winning_move(col, row):
self.is_game_over = True
return 1
return 0
def take_action(self, col: int) -> float:
'''
Moves the current player into the specified column.
Also records history for the move
Returns the reward for making such a move
'''
state = self.get_state()
reward = self._actually_take_action(col)
self.history.append((state, col, reward))
return reward
def get_state(self) -> str:
'''
Board's __str__ method returns a string of 0s 1s and 2s (for empty, red, black cells as per the Cell enum)
This method converts such a string to Es, Ms, and Ys which stand for Empty, My cells, and Your cells
'''
board_str = str(self.b)
if self.cur_player == Cell.BLACK:
board_str = board_str.replace(str(Cell.BLACK.value), 'M') # Mine
board_str = board_str.replace(str(Cell.RED.value), 'Y') # Yours
board_str = board_str.replace(str(Cell.EMPTY.value), 'E') # Empty
else:
board_str = board_str.replace(str(Cell.RED.value), 'M') # Mine
board_str = board_str.replace(str(Cell.BLACK.value), 'Y') # Yours
board_str = board_str.replace(str(Cell.EMPTY.value), 'E') # Empty
return board_str
def test_check_winning_off_second_diagonal_win():
b = Board(3, 3, 2)
b.cells[1, 0] = Cell.BLACK
b.cells[2, 1] = Cell.BLACK
assert b.check_winning_move(1, 0)
assert b.check_winning_move(2, 1)
def test_check_winning_off_main_diagonal_win():
b = Board(3, 3, 2)
b.cells[0, 1] = Cell.BLACK
b.cells[1, 2] = Cell.BLACK
assert b.check_winning_move(0, 1)
assert b.check_winning_move(1, 2)
def test_check_winning_move_second_diagonal_win():
b = Board(2, 2, 2)
b.cells[0, 0] = Cell.BLACK
b.cells[1, 1] = Cell.BLACK
assert b.check_winning_move(1, 1)
assert b.check_winning_move(0, 0)
