.join函数在循环中不起作用

Question

下面的函数是否正确使用.join函数？我试图在没有引号和逗号的情况下制作所有O的板.输出与电路板输入相同,不删除逗号或引号.我是Python的新手,所以我还没有掌握使用这些内置函数的正确方法.

board = []
for x in range(5):
    board.append(['O'] * 5)

def print_board(oChart):
    for row in oChart:

        #this line below is were the error occurs
        " ".join(row)

        print row


print_board(board)

运行时输出为:

['O','O','O','O','O']
['O','O','O','O','O']
['O','O','O','O','O']
['O','O','O','O','O']
['O','O','O','O','O']

我打算收到的输​​出:

[O O O O O]
[O O O O O]
[O O O O O]
[O O O O O]
[O O O O O]

Answer 1

join 返回字符串.它没有改变row.做print " ".join(row).

请注意,这不包括括号.如果你想要它们,你需要自己打印.

Answer 2

问题是你没有做任何事情来保存价值" ".join(row).您正在连接字符串,然后丢弃结果.

试试print " ".join(row).