如何使用用户输入更改列表元素？

Question

I'm trying to change an element of a list by doing this:

board = []
for i in range(3):
    board.append("-"*3)

def print_board(board):
    for row in board:
        print " ".join(row)

print_board(board)
print "Welcome to tic tac toe. You go first because I say so."
column = int(raw_input("Enter column number: "))
row = int(raw_input("Enter row number: "))

board[row][column] = "O" #THIS ONE
print_board(board)

but the error message "TypeError: 'str' object does not support item assignment" shows up. What should I do?

Answer 1

'-' * 3 is a string and you want a list.

So you should replace this :

board.append("-"*3) # '---'

with this :

board.append(['-']*3) # ['-','-','-']