how to code a tic tac toe game with ai python

1#Tic Tac Toe game in python by techwithtim
2
3board = [' ' for x in range(10)]
4
5def insertLetter(letter, pos):
6    board[pos] = letter
7
8def spaceIsFree(pos):
9    return board[pos] == ' '
10
11def printBoard(board):
12    print('   |   |')
13    print(' ' + board[1] + ' | ' + board[2] + ' | ' + board[3])
14    print('   |   |')
15    print('-----------')
16    print('   |   |')
17    print(' ' + board[4] + ' | ' + board[5] + ' | ' + board[6])
18    print('   |   |')
19    print('-----------')
20    print('   |   |')
21    print(' ' + board[7] + ' | ' + board[8] + ' | ' + board[9])
22    print('   |   |')
23    
24def isWinner(bo, le):
25    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)
26
27def playerMove():
28    run = True
29    while run:
30        move = input('Please select a position to place an \'X\' (1-9): ')
31        try:
32            move = int(move)
33            if move > 0 and move < 10:
34                if spaceIsFree(move):
35                    run = False
36                    insertLetter('X', move)
37                else:
38                    print('Sorry, this space is occupied!')
39            else:
40                print('Please type a number within the range!')
41        except:
42            print('Please type a number!')
43            
44
45def compMove():
46    possibleMoves = [x for x, letter in enumerate(board) if letter == ' ' and x != 0]
47    move = 0
48
49    for let in ['O', 'X']:
50        for i in possibleMoves:
51            boardCopy = board[:]
52            boardCopy[i] = let
53            if isWinner(boardCopy, let):
54                move = i
55                return move
56
57    cornersOpen = []
58    for i in possibleMoves:
59        if i in [1,3,7,9]:
60            cornersOpen.append(i)
61            
62    if len(cornersOpen) > 0:
63        move = selectRandom(cornersOpen)
64        return move
65
66    if 5 in possibleMoves:
67        move = 5
68        return move
69
70    edgesOpen = []
71    for i in possibleMoves:
72        if i in [2,4,6,8]:
73            edgesOpen.append(i)
74            
75    if len(edgesOpen) > 0:
76        move = selectRandom(edgesOpen)
77        
78    return move
79
80def selectRandom(li):
81    import random
82    ln = len(li)
83    r = random.randrange(0,ln)
84    return li[r]
85    
86
87def isBoardFull(board):
88    if board.count(' ') > 1:
89        return False
90    else:
91        return True
92
93def main():
94    print('Welcome to Tic Tac Toe!')
95    printBoard(board)
96
97    while not(isBoardFull(board)):
98        if not(isWinner(board, 'O')):
99            playerMove()
100            printBoard(board)
101        else:
102            print('Sorry, O\'s won this time!')
103            break
104
105        if not(isWinner(board, 'X')):
106            move = compMove()
107            if move == 0:
108                print('Tie Game!')
109            else:
110                insertLetter('O', move)
111                print('Computer placed an \'O\' in position', move , ':')
112                printBoard(board)
113        else:
114            print('X\'s won this time! Good Job!')
115            break
116
117    if isBoardFull(board):
118        print('Tie Game!')
119
120while True:
121    answer = input('Do you want to play again? (Y/N)')
122    if answer.lower() == 'y' or answer.lower == 'yes':
123        board = [' ' for x in range(10)]
124        print('-----------------------------------')
125        main()
126    else:
127        break