Swimming with snake pt1

from collections import defaultdict
def make_dice_board():
    board = defaultdict(lambda:defaultdict(lambda:0))
    for i in range(40):
        for j in range(i+1, i+7):
            board[i][j] = 1./6
    full_board = {}
    for i in range(40):
        full_board[i] = {}
        for j in range(40):
            full_board[i][j] = board[i][j]
    return full_board