Python面向对象编程——一些类定义（杂）

一、abstractmethod

• 子类必须全部实现重写父类的abstractmethod方法
• 非abstractmethod方法可以不实现重写
• 带abstractmethod方法的类不能实例化

  from abc import abstractmethod, ABCMeta

 1 class BettingStrategy(metaclass=ABCMeta):
 2
 3     @abstractmethod
 4     def bet(self):
 5         print('0')
 6
 7     def record_win(self):
 8         print('win')
 9
10     def record_loss(self):
11         print('loss')
12
13
14 class Bet(BettingStrategy):
15     def bet(self):
16         print('1')

扩展：abc模块

二、staticmethod：静态函数

对象不用实例化即可调用的函数

 1 class Hand4:
 2     def __init__(self, dealer_card, *cards):
 3         self.dealer_card = dealer_card
 4         self.cards = cards
 5
 6     @staticmethod
 7     def freeze(other):
 8         hand = Hand4(other.dealer_card, *other.cards)
 9         return hand
10
11     @staticmethod
12     def split(other, card0, card1):
13         hand0 = Hand4(other.dealer_card, other.cards[0], card0)
14         hand1 = Hand4(other.dealer_card, other.cards[1], card1)
15         return hand0, hand1
16
17     def __str__(self):
18         return ','.join(map(str, self.cards))

1 h41 = Hand4(deck3.pop(), deck3.pop(), deck3.pop())
2     s1, s2 = Hand4.split(h41, deck3.pop(), deck3.pop())
3     s3 = Hand4.freeze(h41)

调用