STARTING = [[10,10],[9,10],[11,10],[11,9],[10,8]]

XSIZE = 20
YSIZE = 20

def init_board ():
    """
    This function creates an instance of the board with XSIZE by
    YSIZE cells. All cells are set to False initially.
    """
    board = []
    for y in range(0,YSIZE):
        board = board + [[False] * XSIZE]
    return board


def set_starting_conf(board):
    """
    This function sets those cells specified in the variable STARTING
    to True.
    """
    for pos in STARTING:
        board[pos[1]][pos[0]] = True
    

def printcell(board,x,y):
    """
    This function prints an 'o' if the cell at position x, y is True
    and '-' if that cell is False.
    """
    if board[y][x]:
        print 'o',
    else:
        print '-',


def display_board (board):
    """
    This function prints out a representation of the board.
    """
    print
    for y in range(0,YSIZE):
        for x in range(0,XSIZE):
            printcell(board,x,y)
        print
    print


def life_neighbors(board,x,y):
    """
    This function takes the representation of the board and two integers, x and y,
    indicating a position on the board. Complete this function so that it counts
    how many life neighbors the cell at position x,y has and returns that number.
    Assume that the board wraps around. That is, if the cell is at the edge of the
    board, some of its neighbors will be at the opposite edge of the board. The cell
    at position x,y should not be counted as its own neighbor.
    """
    n = 0
    ### ADD YOUR CODE HERE
    return n

def update_board(board):
    """
    This function takes the board representation as parameter. Complete this
    function such that it calculates what the board in the next generation
    should look like. 
    """
    new_board = init_board()
    ### ADD YOUR CODE HERE
    return new_board
    

def main ():
    board = init_board()
    set_starting_conf(board)
    display_board(board)
    more = raw_input("Press return for the next step; 'q' and return to stop\n")
    while more != 'q':
        board = update_board(board)
        display_board(board)
        more = raw_input("Press return for the next step; 'q' and return to stop\n")

main()