remove color codes from list of lists before saving to file

Question

Im working wiht a list of lists that ended up containing color codes surrounding integer elements in the sublists. This list of lists is meant to be printed into the console as a sudoku grid with gray cells by using a function that replaces the element already present, according to a coordinates list, by the element surrounded by the color codes. However, it would be ideal if i could not save the color codes into the file by removing them priorly or not having them saved into a variable.

This is the function used to save into a file:

def board_saver(board,str_filename):
    filename = open(str_filename,'w')
    for i in board:
        if board.index(i) == 0:
            filename.write("[%s,\n" % i)
        else:
            filename.write("%s,\n" % i if board.index(i) in [1,2,3,4,5,6,7] else "%s]\n" % i) 
    filename.close()

And this is the function used to read the same list of lists into python again, including, allowing further filling of the list of lists through the console:

def board_reader(str_filename):
    file1 = open(str_filename, 'r')
    board2 = eval(file1.read())
    print(type(board2))
    file1.close()
    return board2

Here is what i have been saving into a file:

[[5, 7, ' ', 8, 2, ' ', 4, ' ', ' '],
[3, '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m \x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m \x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m9\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m \x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', 6, ' ', 5, ' '],
[' ', '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m \x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', 1, ' ', ' ', ' ', ' ', 3, 7],
[2, '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m \x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m \x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m \x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m7\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', ' ', 8, 1, ' '],
[' ', 1, '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m \x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', ' ', 4, ' ', '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m \x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', 6, ' '],
[7, 4, ' ', ' ', ' ', ' ', '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m8\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', ' ', ' '],
[' ', ' ', 5, ' ', ' ', ' ', '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m5\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m9\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m', '\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m\x1b[1;37;40m \x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m\x1b[0m']]

The functions that produce the list of lists above are:

    
    print("gray cells:",coordinates_list,)
    sudoku2 = board                            
    for i in coordinates_list: 
        element = i
        x = int(element[-1])
        y = int(element[0])
        
        if element == "{}{}".format(y,x) :
            sudoku2[y][x] = "\033[1;37;40m{}\033[0m".format(board[y][x])
    return sudoku2


def sudoku_printer(coordinates_list, board):
    """ Prints a board line by line with the elements from sudoku_board being placced in the
    {} place holders by the comprehention list in the format function. Because of board_fuser
    indexes qith zero are printed with a grey color"""
    board1 = board
    fused_board = board_fusor(coordinates_list, board1)
    print("fused board", board1)
    board_header2 = " 1   2   3   4   5   6   7   8   9"
    row_names = ["A", "B", "C", "D", "E", "F", "G", "H", "I"]
    print("\n", board_header2)
    print("-"*37)
    for i, row in enumerate(fused_board):
        print(("|" + " {}   {}   {} |"*3).format(*[x if x != 0 else "{}".format(x) for x in row]),row_names[i])
        if i == 8:
            print("-"*37)
        elif i % 3 == 2:
            print("|" + "---+"*8 + "---|")
        else:
            print("|" + "   +"*8 + "   |")

When it should be/look like this:

[[5, 7, ' ', 8, 3, ' ', 4, ' ', ' '],
[3, ' ', ' ', 9, ' ', ' ', ' ', 5, ' '],
[' ', ' ', 1, ' ', ' ', ' ', ' ', 3, 7],
[' ', ' ', ' ', ' ', 7, ' ', 8, 1, ' '],
[2, ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '],
[1, ' ', ' ', ' ', 8, ' ', ' ', ' ', 6],
[' ', 1, ' ', ' ', 4, ' ', ' ', 6, ' '],
[7, 4, ' ', ' ', ' ', ' ', 8, ' ', ' '],
[' ', ' ', 5, ' ', ' ', ' ', 5, 9, ' ']]

Can anyone help me please? What should I do to remove the color code part from the elements of the list of lists or to remove it after reading it from the file? Is there an answer like: remove color codes from console text output to do that? I do not understand RegEx.