#游戏开始，首先玩家选择大小，选择完成后开始摇骰子（11<=总值<=18为大，3<=总值<=10为小）

import random

def roll_dice(numbers=3,points=None):          # 创建3个筛子numbers，创建点数points

    print('<<<<roll the dice!>>>>')

    if points is None:

        points = []                             # 把点数放到一个空的列表里

    while numbers > 0:

        point = random.randrange(1,7)

        points.append(point)

        numbers = numbers - 1

    return points

def roll_result(total):                 # 判断大小

    isbig = 11 <= total <= 18

    issmall = 3 <= total <=10

    if isbig:

        return 'big'

    elif issmall:

        return 'small'

def start_game():

    print('<<<<GAME STRATS!>>>>')

    choices = ['big','small']

    your_choice = input('big or small:')

    if your_choice in choices:

        points = roll_dice()

        total = sum(points)

        youwin = your_choice == roll_result(total)

        if youwin:

            print('The points are',points,'YOU WIN!')

        else:

            print('The points are',points,'YOU LOSE!')

    else:

        print('invalid words')

        start_game()

start_game()