Immediate Help with python program!

[Daniel]

i am making a tic-tac-toe game using python. i am pretty new to it,
but cant seem to figure this one out.
Here is my code:

X = "X"
O = "O"
empty = " "
tie = "Tie"
squares = 9

def display():
    print """Welcome to Tic-Tac-Toe. Player will play against the
computer.
            \nYou will move by typing in the number to the
corresponding square below:

                  0 | 1 | 2
                -------------
                  3 | 4 | 5
                -------------
                  6 | 7 | 8 \n"""


def select():
    question = ask("Do you want to go first? (y/n)")
    if question == "y":
        player = X
        computer = O
    else:
        computer = X
        player = O
    return computer, player

def newBoard():
    board = []
    for i in range(squares):
        board.append(empty)
    return board

def displayBoard(board):
    print "\n\t", board[0], "|", board[1], "|", board[2]
    print "\t", "---------"
    print "\t", board[3], "|", board[4], "|", board[5]
    print "\t", "---------"
    print "\t", board[6], "|", board[7], "|", board[8], "\n"

def boardMoves(board):
    moves = []
    for i in range(squares):
        if board[i] == empty:
            moves.append(i)
    return moves

def findWinner(board):
    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 i in win:
        if board[i[0]] == board[i[1]] == board[i[2]] != empty:
            winner = board[i[0]]
            return winner
        if empty not in board:
            return tie
        return None

def askMove(question, low, high):
    response = None
    while response not in range(low, high):
        response = int(raw_input(question))
    return response


def playerMove(board, player):
    legal = boardMoves(board)
    move = None
    while move not in legal:
        move = askMove("Pick a number where you want to move(0-8):",
0, squares)
        if move not in legal:
            print "\nThat move is taken already. Pick another."
    return move

def compMove(board, computer, player):
    board = board[:]
    strategy = (4, 0, 2, 6, 8, 1, 3, 5, 7)
    print "Computer chooses:",

    # if computer can win, take that move
    for move in boardMoves(board):
        board[move] = computer
        if findWinner(board) == computer:
            print move
            return move
        board[move] = empty

    # if human can win, block that move
    for move in boardMoves(board):
        board[move] = player
        if findWinner(board) == player:
            print move
            return move
        board[move] = empty

    # If no one can win pick best open square
    for move in strategy:
        if move in boardMoves(board):
            print move
            return move

def nextTurn(turn):
    if turn == X:
        return 0
    else:
        return X

def gameWinner(winner, computer, player):
    if winner == computer:
        print "Computer Wins. Better luck next time"
    elif winner == player:
        print "You win. Good job!"
    elif winner == tie:
        print "Tie game. Play again."

def main():
    display()
    computer, player = select()
    turn = X
    board = newBoard()
    displayBoard(board)

    while not findWinner(board):
        if turn == player:
            move = playerMove(board, player)
            board[move] = player
        else:
            move = compMove(board, computer, player)
            board[move] = computer
        displayBoard(board)
        turn = nextTurn(turn)
    winner = findWinner(board)
    gameWinner(winner, computer, player)



main()

Here is my problem:
If you hit 'n' at the beginning prompt, the computer does four moves
automatically and wins- you can't input anything. If you hit 'y' at
the beginning prompt, you can play but cannot win. I got three x's in
a row and it didn't let me win. It just keeps letting
you input numbers until the computer wins even if you have three in a
row.


If anyone can help please do asap.
Thank you!