Python: Getting error when guessing wrong on battleship style game

I am trying to make a battleship type of game where there is a 3 by 3 board with one random point on the board that you are trying to guess. You should have 2 tries to guess the point, with an incorrect guess leaving an x in place of the o on the board.

The error is for this line:
board[int(guess_row)][int(guess_column)] = "x"
It says TypeError: ‘str’ object does not support item assignment

     board = []
            for row in range(3):
                board.append("o" * 3)
            def print_board(board):
                for row in board:
                    print(" ".join(row))
            print_board(board)
            stone_row = randint(1, 3)
            stone_column = randint(1, 3)
            print(stone_row)
            print(stone_column)
            for turn in range(2):
                response_row = 0
                while response_row == 0:
                    guess_row = input("""
Cup Man: So, what row do you guess?
""")
                    valid_cup = ["1", "2", "3"]
                    if guess_row in valid_cup:
                        response_row = 1
                response_column = 0
                while response_column == 0:
                    guess_column = input("""
Cup Man: And what column?
""")
                    if guess_column in valid_cup:
                        response_column = 1
                if int(guess_row) == stone_row and int(guess_column) == stone_column:
                    print("""
The man lifts up the cup that you guessed.""")
                    input("")
                    print("""
The stone is there!""")
                    input("")
                    print("""
Cup Man: Guess you win. Here's 60 gold.""")
                    gold += 60
                    break
                else:
                    if (int(guess_row) < 1 or int(guess_row) > 3) or (int(guess_column) < 1 or int(guess_column) > 3):
                        print("""
Cup Man: That's not right...""")
                    elif board[int(guess_row)][int(guess_column)] == "x":
                        print("""
Cup Man: You just guessed that one genius...""")
                    else:
                        print("""
The man lifts up the cup that you guessed.""")
                        input("")
                        print("""
There's nothing there.""")
                        input("")
                        print("""
Cup Man: Too bad. Wrong choice.""")
                        board[int(guess_row)][int(guess_column)] = "x"
                        turn += 1
                        print_board(board)
                    if turn == 2:
                        print("""
Cup Man: That's it. You lose.""")

>Solution :

You can’t list that index since it doesn’t exist. If you want to reference a specific ‘o’ for each index, you need to turn each ‘o’ per string into its own list of o’s.

board = []
for row in range(3):
board.append(["o"] * 3) <– Put brackets

print(board)


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