Что не так с моей функцией computer_move?

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TIE = "Tie"
O = 'O'
X = 'X'
EMPTY = " "
winner = 0 
def instructions():
    print ('''
    0 : 1 : 2
    ----------
    3 : 4 : 5
    ----------
    6 : 7 : 8
''')

def who_goes_first():
    answer = None
    while answer not in ('y','n'):
        answer = input ('You want to go first? "y" or "n".')
    if answer == 'y':
        human = X
        computer = O
    elif answer == 'n':
        human = O
        computer = X
    return human, computer, answer


def empty_board():
    board = []
    for square in range (9):
        board.append(EMPTY)
    return board
def display_board(board):
    print (board[0],':' ,board[1],':', board[2]) 
    print ('----------')
    print (board[3], ':', board[4], ':', board[5])
    print ('----------')
    print (board[6], ':', board[7], ':', board[8])
def legal_move(board):
    legal = []
    unlegal = []
    for square in range(9):
        if board[square] == EMPTY:
            legal.append(square)
        elif board[square] != EMPTY:
            unlegal.append(square)
    return legal, unlegal
def human_move(human, board, legal):
    move = None
    print ('Moves you are allowed:', legal)
    while move not in legal:
        move = int(input ('Enter your move:'))    
    return move
def computer_move (human, computer, board, unlegal):
    way_to_win = [(0,1,2),
                  (3,4,5),
                  (6,7,8),
                  (0,3,6),
                  (1,4,7),
                  (2,5,8),
                  (0,4,8),
                  (2,4,6)]
    priority = [4, 0, 8, 6, 2, 1, 3, 7, 5]
    for number in unlegal:
        if number in priority:
            priority.remove(number)
    for row in way_to_win:
        if board[row[0]] == board[row[1]] == computer and board[row[2]] == EMPTY:           
            move = row[2]    
        elif board[row[1]] == board[row[2]] == computer and board[row[0]] == EMPTY:
            move = row[0]     
        elif board[row[0]] == board[row[2]] ==computer and board[row[1]] == EMPTY:
            move = row[1]
        if board[row[0]] == board[row[1]] == human and board[row[2]] == EMPTY:           
            move = row[2]    
        elif board[row[1]] == board[row[2]] == human and board[row[0]] == EMPTY:
            move = row[0]     
        elif board[row[0]] == board[row[2]] == human and board[row[1]] == EMPTY:
            move = row[1] 
        else:
            move = priority[0]
        break
    return move         
def switch_turn(board, answer, computer, human):
    human_count = 0
    computer_count = 0
    for square in board:
        if square == computer:
            computer_count +=1
        elif square == human:
            human_count += 1
    if answer == 'y' and human_count == computer_count:
        human_turn = 1
    elif answer == 'y' and human_count > computer_count:
        human_turn = 0
    elif answer == 'n' and human_count == computer_count:
        human_turn = 0
    elif answer == 'n' and computer_count > human_count:
        human_turn = 1
    return human_turn
def return_board(human, computer, board, move):
    if human_turn == 1:
        board[move] = human
    elif human_turn == 0:
        board[move] = computer
    return board
def outcome(board, human, computer):
    global winner
    way_to_win = [(0,1,2),
                  (3,4,5),
                  (6,7,8),
                  (0,3,6),
                  (1,4,7),
                  (2,5,8),
                  (0,4,8),
                  (2,4,6)]
    
    for row in way_to_win:
        
        if board[row[0]] == board[row[1]] == board[row[2]] == human:    
            winner = human     
        elif board[row[0]] == board[row[1]] == board[row[2]] == computer:
            winner = computer
        elif EMPTY not in board:
            winner = TIE
    return winner

### MAIN PROGRAM

instructions()
human, computer, answer = who_goes_first()
board = empty_board()
display_board(board)
while winner == 0:
    human_turn = switch_turn(board, answer, computer, human)
    legal,unlegal = legal_move(board)
    if human_turn == 1:
        move = human_move(human, board, legal)
        print ('\n***********\n')
    elif human_turn ==0:
        move = computer_move (human, computer, board, unlegal)
        print ('\n***********\n')
    board = return_board(human, computer, board,move)
    display_board(board)
    winner = outcome(board, human, computer)
if winner == TIE:
    print ('It\'s a draw')
if winner in (human, computer):
    print ('{0} won.'.format(winner))

Что я уже пробовал:

Я пытаюсь сделать программу "крестики-нолики". Я пытаюсь заставить компьютер блокировать, если игрок собирается выиграть, или продолжать, если он собирается выиграть,но его ход неустойчив. Что не так с моей логикой?

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