Minimax

def minimax(current_board,isMaximize):
    global winner
    winner = 'None'
    who_won(current_board)
    if winner == 'O':
        return 1
    if winner == 'X':
        return -1
    if winner == 'Tie':
        return 0
    score = 0
    if isMaximize:
        best_score = -10000        
        for i in range(9):
            if board[i] == '-':
                current_board[i] = 'O'
                score = minimax(current_board,False)
                current_board[i] = '-'
                best_score = max(best_score, score)
        return best_score
    else:
        best_score = 10000
        for i in range(9):
            if board[i] == '-':
                current_board[i] = 'X'
                score = minimax(current_board,True)
                current_board[i] = '-'
                best_score = min(best_score, score)
        return best_score