A grid is a perfect starting point for many games (Chess, battleships, Candy Crush!).
Making a digital chessboard I think is an interesting way of visualising how loops can work together.
Your task is to write a function that takes two integers `rows` and `columns` and returns a chessboard pattern as a two dimensional array.
So `chessBoard(6,4)` should return an array like this:
    [
            ["O","X","O","X"],
            ["X","O","X","O"],
            ["O","X","O","X"],
            ["X","O","X","O"],
            ["O","X","O","X"],
            ["X","O","X","O"]
    ]
And `chessBoard(3,7)` should return this:
    [
        ["O","X","O","X","O","X","O"],
        ["X","O","X","O","X","O","X"],
        ["O","X","O","X","O","X","O"]
    ]
The white spaces should be represented by an: `'O'`
and the black an: `'X'`
The first row should always start with a white space `'O'`
def chess_board(rows, columns):
    board = []
    for row in range(rows):
        if row % 2:
            board.append(["X" if not column % 2 else "O" for column in range(columns)])
        else:
            board.append(["O" if not column % 2 else "X" for column in range(columns)])
    return board
def chess_board(rows, columns):
    board = []
    for row in range(rows):
        if row % 2:
            board.append(["X" if not column % 2 else "O" for column in range(columns)])
        else:
            board.append(["O" if not column % 2 else "X" for column in range(columns)])
    return board