剛學Python，一個粗糙列印井字棋盤的程式碼

下面展示一些 內聯程式碼片。

// 
def printboard(board):
    print(board[top_L]+'|'+board[top_M]+'|'+board[top_R])
    print('-+-+-')
    print(board[mid-L]+'|'+board[mid-M]+'|'+board[mid-R])
    print('-+-+-')
    print(board[low-L]+'|'+board[low-M]+'|'+board[low-R])
theBoard={'top_L': '','top_M': '','top-_R': '',
           'mid-L': '','mid-M': '','mid-R': '',
           'low-L': '','low-M': '','low-R': ''}
printboard(theBoard)

問題

跪求幫助