Chess in Python: list indices must be integers, not str

Question

I wrote early version of chess in python. I have a problem with this:

File "C:/Users/Goldsmitd/PycharmProjects/CHESS/chess_ver0.04.py", line 39, in move self.board[destination_x][destination_y] = 1 TypeError: list indices must be integers, not str

my code:

class Chess_Board:
    def __init__(self):
        self.board = self.create_board()

    def create_board(self):
        board_x=[]

        for x in range(8):
            board_y =[]
            for y in range(8):
                if (x==7 and y==4):
                    board_y.append('K')

                elif (x== 7 and y == 3):
                   board_y.append('Q')

                else:
                   board_y.append('.')

            board_x.append(board_y)

        return board_x


class WHITE_KING(Chess_Board):
    def __init__(self):
        Chess_Board.__init__(self)
        self.symbol = 'K'
        self.position_x = 7
        self.position_y = 4


    def move (self):

        print ('give x and y cordinates fo white king')
        destination_x = input()
        destination_y = input()

        self.board[destination_x][destination_y] = 'K'

I don't know what does not work

Answer 1

The value recieved from input() has a 'string' type (even if it looks like number), so you should convert it to integer.

self.board[int(destination_x)][int(destination_y)] = 'K'

The code above will fail if you enter something else than digits, so it is better to add an additional check before:

def move (self):
    destination_x = None
    destination_y = None
    while not (destination_x and destination_y):
        print ('give x and y cordinates fo white king')
        try:
            destination_x = int(input())
            destination_y = int(input())
        except ValueError as e:
            pass
    self.board[destination_x][destination_y] = 'K'