day30 纸牌游戏

 import json
 from collections import namedtuple

 Card = namedtuple('Card', ['rank', 'suit'])  # rank 牌面的大小 suit牌面的花色

 class FranchDeck:
     ranks = [str(n) for n in range(2, 11)] + list('JQKA')  # 2-A
     suits = ['红心', '方板', '梅花', '黑桃']

     def __init__(self):
         self._cards = [Card(rank, suit) for rank in FranchDeck.ranks
                        for suit in FranchDeck.suits]

     def __len__(self):
         return len(self._cards)

     def __getitem__(self, item):
         return self._cards[item]

     def __setitem__(self, key, value):
         self._cards[key] = value

     def __str__(self):
         return json.dumps(self._cards, ensure_ascii=False)

 deck = FranchDeck()
 print(deck)
 # [["2", "红心"], ["2", "方板"], ["2", "梅花"], ["2", "黑桃"], ["3", "红心"],
 # ["3", "方板"], ["3", "梅花"], ["3", "黑桃"], ["4", "红心"], ["4", "方板"],
 # ["4", "梅花"], ["4", "黑桃"], ["5", "红心"], ["5", "方板"], ["5", "梅花"],
 # ["5", "黑桃"], ["6", "红心"], ["6", "方板"], ["6", "梅花"], ["6", "黑桃"],
 # ["7", "红心"], ["7", "方板"], ["7", "梅花"], ["7", "黑桃"], ["8", "红心"],
 # ["8", "方板"], ["8", "梅花"], ["8", "黑桃"], ["9", "红心"], ["9", "方板"],
 # ["9", "梅花"], ["9", "黑桃"], ["10", "红心"], ["10", "方板"], ["10", "梅花"],
 # ["10", "黑桃"], ["J", "红心"], ["J", "方板"], ["J", "梅花"], ["J", "黑桃"],
 # ["Q", "红心"], ["Q", "方板"], ["Q", "梅花"], ["Q", "黑桃"], ["K", "红心"],
 # ["K", "方板"], ["K", "梅花"], ["K", "黑桃"], ["A", "红心"], ["A", "方板"],
 # ["A", "梅花"], ["A", "黑桃"]]

 print(deck[10]) # 索引为10 的 Card(rank='4', suit='梅花')
 from random import choice  # choice 依赖于len
 print(choice(deck))
 print(choice(deck))

 from random import shuffle  # 洗牌，shuffle依赖于setitem
 shuffle(deck)
 print(deck[10])