2025年内置函数ltems、new、hash、eq

科技前沿 • 2025-02-15 21:59 • 阅读 55

大家好，我是讯享网，很高兴认识大家。

getitems setitems delitmes dic = {'k':'v'} # 对象 ： 存储属性 和调用方法 dic['k'] = 'v' class Foo: def __init__(self,name,age,sex): self.name = name self.age = age self.sex = sex def __getitem__(self, item): if hasattr(self,item): return self.__dict__[item] def __setitem__(self, key, value): self.__dict__[key] = value def __delitem__(self, key): del self.__dict__[key] f = Foo('egon',38,'男') print(f['name']) f['hobby'] = '男' print(f.hobby,f['hobby']) del f.hobby # object 原生支持 __delattr__ del f['hobby'] # 通过自己实现的 print(f.__dict__)

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new

讯享网# 设计模式 # 23种 # 单例模式 # 一个类 始终 只有 一个 实例 # 当你第一次实例化这个类的时候 # __init__ 初始化方法 # __new__ 构造方法 : 创建一个对象 class A: def __init__(self): self.x = 1 print('in init function') def __new__(cls, *args, kwargs): print('in new function') return object.__new__(A, *args, kwargs) a1 = A() a2 = A() a3 = A() print(a1)就创建一个实例化的对象 # 当你之后再来实例化的时候 就用之前创建的对象 class A: __instance = False def __init__(self,name,age): self.name = name self.age = age def __new__(cls, *args, kwargs): if cls.__instance: return cls.__instance cls.__instance = object.__new__(cls) return cls.__instance egon = A('egg',38) egon.cloth = '小花袄' nezha = A('nazha',25) print(nezha) print(egon) print(nezha.name) print(egon.name) print(nezha.cloth)

hash

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hash() #__hash__ class A: def __init__(self,name,sex): self.name = name self.sex = sex def __hash__(self): return hash(self.name+self.sex) a = A('egon','男') b = A('egon','nv') print(hash(a)) print(hash(b))

讯享网class A: def __init__(self,name): self.name = name def __eq__(self, other): if self.__dict__ == other.__dict__: return True else: return False ob1 = A('egon') ob2 = A('egg') print(ob1 == ob2) 案例 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[10]) from random import choice print(choice(deck)) #随机抽取 # print(choice(deck)) from random import shuffle shuffle(deck)#洗牌 print(deck[10]) print(deck) print(deck[:5])

2025年内置函数ltems、new、hash、eq

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