OBJECTIVE:Tic Tac Toe. We will learn to make TicTacToe game using Python.

CODE:

import random
class TicTacToe(object):
winning_combos = (
[0, 1, 2], [3, 4, 5], [6, 7, 8],
[0, 3, 6], [1, 4, 7], [2, 5, 8],
[0, 4, 8], [2, 4, 6]
)

winners = ('X-win', 'Draw', 'O-win')

def __init__(self, board=[]):
'''
Initialize the tic tac toe board
:param board: 1-D list of board positions
'''
if len(board) == 0:
self.board = [0 for i in range(9)]
else:
self.board = board
def print_board(self):
'''
Printing the tic tac toe board
'''
for i in range(3):
print(
"| " + str(self.board[i * 3]) +
" | " + str(self.board[i * 3 + 1]) +
" | " + str(self.board[i * 3 + 2]) + " |"
)
def check_game_over(self):

''' Check if the game is over or there is a winner '''

if 0 not in [element for element in self.board]:
return True
if self.winner() != 0:
return True
return False
def available_moves(self):
''' To check what all possible moves are remaining for a player '''
return [index for index, element in enumerate(self.board) if element is 0]
def available_combos(self, player):
''' To check what are the possible places to play for winning the game '''
return self.available_moves() + self.get_acquired_places(player)
def X_won(self):
return self.winner() == 'X'
def O_won(self):
return self.winner() == 'O'
def is_tie(self):
return self.winner() == 0 and self.check_game_over()
def winner(self):
'''
Checks for the winner of the game
:return player: return 'X' or 'O' whoever has won the game
else returns 0
'''
for player in ('X', 'O'):
positions = self.get_acquired_places(player)
for combo in self.winning_combos:
win = True
for pos in combo:
if pos not in positions:
win = False
if win:
return player
return 0
def get_acquired_places(self, player):
'''
To get the positions already acquired by a particular player
:param player: 'X' or 'O'
'''
return [index for index, element in enumerate(self.board) if element == player]
def make_move(self, position, player):
self.board[position] = player
def minimax(self, node, player):
'''
Minimax algorithm for choosing the best possible move towards
winning the game
'''
if node.check_game_over():
if node.X_won():
return -1
elif node.is_tie():
return 0
elif node.O_won():
return 1
best = 0
for move in node.available_moves():
node.make_move(move, player)
val = self.minimax(node, get_enemy(player))
node.make_move(move, 0)
if player == 'O':
if val > best:
best = val
else:
if val < best:
best = val
return best

def determine(board, player):
'''
Driver function to apply minimax algorithm
'''
a = 0
choices = []
if len(board.available_moves()) == 9:
return 4
for move in board.available_moves():
board.make_move(move, player)
val = board.minimax(board, get_enemy(player))
board.make_move(move, 0)
if val > a:
a = val
choices = [move]
elif val == a:
choices.append(move)
try:
return random.choice(choices)
except IndexError:
return random.choice(board.available_moves())
def get_enemy(player):
if player == 'X':
return 'O'
return 'X'
if __name__ == "__main__":
board = TicTacToe()
print('Board positions are like this: ')
for i in range(3):
print(
"| " + str(i * 3 + 1) +
" | " + str(i * 3 + 2) +
" | " + str(i * 3 + 3) + " |"
)
print('Type in the position number you to make a move on..')
while not board.check_game_over():
player = 'X'
player_move = int(input("Your Move: ")) - 1
if player_move not in board.available_moves():
print('Please check the input!')
continue
board.make_move(player_move, player)
board.print_board()
print()
if board.check_game_over():
break
print('Computer is playing.. ')
player = get_enemy(player)
computer_move = determine(board, player)
board.make_move(computer_move, player)
board.print_board()
if board.winner() != 0:
if board.winner() == 'X':
print ("Congratulations you win!")
else:
print('Computer Wins!')
else:
print("Game tied!")