Fluent Python-1(collections.namedtuple & 魔术方法的使用)

import collections # collections — Container datatypes

# namedtuple() Factory Function for Tuples with Named Fields
Card = collections.namedtuple('Card', ['rank', 'suit'])

class FrenchDeck:
    ranks = [str(n) for n in range(2, 11)] + list('JQKA')
    suits = 'spades diamonds clubs hearts'.split()

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

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

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

beer_card = Card('7', 'diamonds')
print('beer_card', beer_card)

# 通过特殊方法 __getitem__ 进行取值
deck = FrenchDeck()
print('deck[-1]', deck[-1])

# 切片操作获取值，通过特殊方法 __getitem__ 进行取值
print('deck[:3]', deck[:3]) # 获取最前面 3 张牌
print('deck[12::13]', deck[12::13]) # 抽出索引为 12 的那张牌，然后每隔 13 张牌拿一张

# 反向迭代
for card in reversed(deck):
    print('card_reversed', card)

# 排序扑克
suit_values = dict(spades=3, hearts=2, diamonds=1, clubs=0) # 生成排序字典
def spades_high(card):
    rank_value = FrenchDeck.ranks.index(card.rank)
    return rank_value * len(suit_values) + suit_values[card.suit]

for card in sorted(deck, key=spades_high):
    print('spades_high,card', card)