how to make a tic tac toe ai in python code example

Example 1: how to code a tic tac toe game with ai python

#Tic Tac Toe game in python by techwithtim

board = [' ' for x in range(10)]

def insertLetter(letter, pos):
    board[pos] = letter

def spaceIsFree(pos):
    return board[pos] == ' '

def printBoard(board):
    print('   |   |')
    print(' ' + board[1] + ' | ' + board[2] + ' | ' + board[3])
    print('   |   |')
    print('-----------')
    print('   |   |')
    print(' ' + board[4] + ' | ' + board[5] + ' | ' + board[6])
    print('   |   |')
    print('-----------')
    print('   |   |')
    print(' ' + board[7] + ' | ' + board[8] + ' | ' + board[9])
    print('   |   |')
    
def isWinner(bo, le):
    return (bo[7] == le and bo[8] == le and bo[9] == le) or (bo[4] == le and bo[5] == le and bo[6] == le) or(bo[1] == le and bo[2] == le and bo[3] == le) or(bo[1] == le and bo[4] == le and bo[7] == le) or(bo[2] == le and bo[5] == le and bo[8] == le) or(bo[3] == le and bo[6] == le and bo[9] == le) or(bo[1] == le and bo[5] == le and bo[9] == le) or(bo[3] == le and bo[5] == le and bo[7] == le)

def playerMove():
    run = True
    while run:
        move = input('Please select a position to place an \'X\' (1-9): ')
        try:
            move = int(move)
            if move > 0 and move < 10:
                if spaceIsFree(move):
                    run = False
                    insertLetter('X', move)
                else:
                    print('Sorry, this space is occupied!')
            else:
                print('Please type a number within the range!')
        except:
            print('Please type a number!')
            

def compMove():
    possibleMoves = [x for x, letter in enumerate(board) if letter == ' ' and x != 0]
    move = 0

    for let in ['O', 'X']:
        for i in possibleMoves:
            boardCopy = board[:]
            boardCopy[i] = let
            if isWinner(boardCopy, let):
                move = i
                return move

    cornersOpen = []
    for i in possibleMoves:
        if i in [1,3,7,9]:
            cornersOpen.append(i)
            
    if len(cornersOpen) > 0:
        move = selectRandom(cornersOpen)
        return move

    if 5 in possibleMoves:
        move = 5
        return move

    edgesOpen = []
    for i in possibleMoves:
        if i in [2,4,6,8]:
            edgesOpen.append(i)
            
    if len(edgesOpen) > 0:
        move = selectRandom(edgesOpen)
        
    return move

def selectRandom(li):
    import random
    ln = len(li)
    r = random.randrange(0,ln)
    return li[r]
    

def isBoardFull(board):
    if board.count(' ') > 1:
        return False
    else:
        return True

def main():
    print('Welcome to Tic Tac Toe!')
    printBoard(board)

    while not(isBoardFull(board)):
        if not(isWinner(board, 'O')):
            playerMove()
            printBoard(board)
        else:
            print('Sorry, O\'s won this time!')
            break

        if not(isWinner(board, 'X')):
            move = compMove()
            if move == 0:
                print('Tie Game!')
            else:
                insertLetter('O', move)
                print('Computer placed an \'O\' in position', move , ':')
                printBoard(board)
        else:
            print('X\'s won this time! Good Job!')
            break

    if isBoardFull(board):
        print('Tie Game!')

while True:
    answer = input('Do you want to play again? (Y/N)')
    if answer.lower() == 'y' or answer.lower == 'yes':
        board = [' ' for x in range(10)]
        print('-----------------------------------')
        main()
    else:
        break

Example 2: tic tac toe python easy

def tic_tac_toe():
    board = [1, 2, 3, 4, 5, 6, 7, 8, 9]
    end = False
    win_commbinations = ((0, 1, 2), (3, 4, 5), (6, 7, 8), (0, 3, 6), (1, 4, 7), (2, 5, 8), (0, 4, 8), (2, 4, 6))

    def draw():
        print(board[0], board[1], board[2])
        print(board[3], board[4], board[5])
        print(board[6], board[7], board[8])
        print()

    def p1():
        n = choose_number()
        if board[n] == "X" or board[n] == "O":
            print("\nYou can't go there. Try again")
            p1()
        else:

             board[n] = "X"
           
    def p2():
        n = choose_number()
        if board[n] == "X" or board[n] == "O":
            print("\nYou can't go there. Try again")
            p2()
        else:
            board[n] = "O"

    def choose_number():
        while True:
            while True:
                a = input()
                try:
                    a  = int(a)
                    a -= 1
                    if a in range(0, 9):
                        return a
                    else:
                        print("\nThat's not on the board. Try again")
                        continue
                except ValueError:
                   print("\nThat's not a number. Try again")
                   continue

    def check_board():
        count = 0
        for a in win_commbinations:
            if board[a[0]] == board[a[1]] == board[a[2]] == "X":
                print("Player 1 Wins!\n")
                print("Congratulations!\n")
                return True

            if board[a[0]] == board[a[1]] == board[a[2]] == "O":
                print("Player 2 Wins!\n")
                print("Congratulations!\n")
                return True
        for a in range(9):
            if board[a] == "X" or board[a] == "O":
                count += 1
            if count == 9:
                print("The game ends in a Tie\n")
                return True

    while not end:
        draw()
        end = check_board()
        if end == True:
            break
        print("Player 1 choose where to place a cross")
        p1()
        print()
        draw()
        end = check_board()
        if end == True:
            break
        print("Player 2 choose where to place a nought")
        p2()
        print()

    if input("Play again (y/n)\n") == "y":
        print()
        tic_tac_toe()

tic_tac_toe()