input: Write a function to implement an AI Tic-Tac-Toe game in Python. The function should handle drawing the game board, checking for a win, and determining the computer's move. If a move is not possible, the game should be declared as drawn.
  
  def playGame():
      board = ['-' for x in range(10)] 
      won = False
      turn = -1
      while not won: 
          if turn == -1: 
              # human turn   
              humanSpot = int(input("Enter your spot: "))
              if board[humanSpot] == '-': 
                  board[humanSpot] = 'X' 
              else: 
                  print("the spot is already filled!") 
                  continue
              turn *= -1
         
          if checkWin(board,'X'): 
              drawBoard(board) 
              print("You won!") 
              won = True
              break
            
          if turn == 1: 
              # computer turn  
              computerSpot = getComputerSpot(board,'O') 
              if computerSpot == None: 
                  drawBoard(board) 
                  print("The game is drawn!")
                  break
              else: 
                  board[computerSpot] = 'O' 
              turn *= -1
                
          drawBoard(board)
  
  assert isinstance(checkWin(board, 'X'), bool)
  assert isinstance(checkWin(board, 'O'), bool)
  assert getComputerSpot(['-', 'X', 'O', 'X', '-', 'O', '-', 'X', '-', 'O'], 'O') in [1, 4, 6, 8]
  assert playGame() is None
output: def playGame():
      board = ['-' for x in range(10)] 
      won = False
      turn = -1
      while not won: 
          if turn == -1: 
              # human turn   
              humanSpot = int(input("Enter your spot: "))
              if board[humanSpot] == '-': 
                  board[humanSpot] = 'X' 
              else: 
                  print("the spot is already filled!") 
                  continue
              turn *= -1
         
          if checkWin(board,'X'): 
              drawBoard(board) 
              print("You won!") 
              won = True
              break
            
          if turn == 1: 
              # computer turn  
              computerSpot = getComputerSpot(board,'O') 
              if computerSpot == None: 
                  drawBoard(board) 
                  print("The game is drawn!")
                  break
              else: 
                  board[computerSpot] = 'O' 
              turn *= -1
                
          drawBoard(board)