def get_next_id(self):
        try:
            query = {'_id': 'last_id'}
            update = {'$inc': {'id': 1}}
            fn = self.db.internal.find_and_modify
            row = fn(query, update, upsert=True, new=True)
        except Exception as e:
            raise DatabaseException(e)
        return row['id']
def circle(self,x,y,r):
		for x_offset in range(-r,r+1):
			for y_offset in range(-r,r+1):
				if sqrt(x_offset**2+y_offset**2)<r:
					self.board[x+x_offset,y+y_offset] = self.color