Python设计模式：享元模式详解-洪萨配资

享元模式的核心思想

享元模式（Flyweight Pattern）通过共享对象减少内存占用，适用于存在大量重复对象的场景。其核心是将对象的内在状态（可共享）与外在状态（不可共享）分离，通过共享内在状态优化资源。

享元模式的结构

Flyweight（抽象享元类）：定义共享对象的接口。
ConcreteFlyweight（具体享元类）：实现抽象享元类，存储内在状态。
FlyweightFactory（享元工厂类）：管理享元对象池，确保对象被合理共享。
Client（客户端）：维护外在状态，调用享元对象。

实现步骤

定义抽象享元接口

from abc import ABC, abstractmethod class Flyweight(ABC): @abstractmethod def operation(self, extrinsic_state): pass

实现具体享元类

class ConcreteFlyweight(Flyweight): def __init__(self, intrinsic_state): self._intrinsic_state = intrinsic_state # 内在状态（共享部分） def operation(self, extrinsic_state): print(f"Shared: {self._intrinsic_state}, Unique: {extrinsic_state}")

享元工厂管理共享

class FlyweightFactory: _flyweights = {} # 享元对象池 @classmethod def get_flyweight(cls, key): if key not in cls._flyweights: cls._flyweights[key] = ConcreteFlyweight(key) return cls._flyweights[key]

客户端使用示例

factory = FlyweightFactory() flyweight_a = factory.get_flyweight("A") # 首次创建并缓存 flyweight_b = factory.get_flyweight("A") # 直接复用 flyweight_a.operation("state1") # 输出: Shared: A, Unique: state1 flyweight_b.operation("state2") # 输出: Shared: A, Unique: state2

应用场景

文本编辑器：字符对象共享（如字母“A”只需一个实例）。
游戏开发：大量相同粒子效果（如子弹、树木）。
数据库连接池：复用连接对象减少开销。

https://www.zhihu.com/zvideo/1992404649416885618/
https://www.zhihu.com/zvideo/1992404649920189696/
https://www.zhihu.com/zvideo/1992404646791230854/
https://www.zhihu.com/zvideo/1992404644815717039/
https://www.zhihu.com/zvideo/1992404644379509727/
https://www.zhihu.com/zvideo/1992404644689904603/
https://www.zhihu.com/zvideo/1992404642911524051/
https://www.zhihu.com/zvideo/1992404641779045977/
https://www.zhihu.com/zvideo/1992404634623574368/
https://www.zhihu.com/zvideo/1992404634430628805/
https://www.zhihu.com/zvideo/1992404632442521330/
https://www.zhihu.com/zvideo/1992404630768985959/
https://www.zhihu.com/zvideo/1992404630718677966/
https://www.zhihu.com/zvideo/1992404629833655108/
https://www.zhihu.com/zvideo/1992404629024166713/
https://www.zhihu.com/zvideo/1992404622791423661/
https://www.zhihu.com/zvideo/1992404628856411164/
https://www.zhihu.com/zvideo/1992404627975591820/
https://www.zhihu.com/zvideo/1992404626985730132/
https://www.zhihu.com/zvideo/1992404626289493675/
https://www.zhihu.com/zvideo/1992404621709291853/
https://www.zhihu.com/zvideo/1992404621038217121/
https://www.zhihu.com/zvideo/1992404618005733708/
https://www.zhihu.com/zvideo/1992404614432170789/
https://www.zhihu.com/zvideo/1992404615543690944/
https://www.zhihu.com/zvideo/1992404614176321614/
https://www.zhihu.com/zvideo/1992404609315132028/
https://www.zhihu.com/zvideo/1992404589270550149/
https://www.zhihu.com/zvideo/1992404587995496693/
https://www.zhihu.com/zvideo/1992404585013326088/
https://www.zhihu.com/zvideo/1992404583436268816/
https://www.zhihu.com/zvideo/1992404582639372230/
https://www.zhihu.com/zvideo/1992404581980865776/
https://www.zhihu.com/zvideo/1992404580936484701/
https://www.zhihu.com/zvideo/1992404580231844821/
https://www.zhihu.com/zvideo/1992404576171741283/
https://www.zhihu.com/zvideo/1992404574590506269/
https://www.zhihu.com/zvideo/1992404575051858971/
https://www.zhihu.com/zvideo/1992404575232213305/
https://www.zhihu.com/zvideo/1992404574632424027/
https://www.zhihu.com/zvideo/1992404574498215281/
https://www.zhihu.com/zvideo/1992404567258854271/
https://www.zhihu.com/zvideo/1992404571532836993/
https://www.zhihu.com/zvideo/1992404571440562947/
https://www.zhihu.com/zvideo/1992404571021123672/
https://www.zhihu.com/zvideo/1992404557834245543/
https://www.zhihu.com/zvideo/1992404559025443249/
https://www.zhihu.com/zvideo/1992404556550797057/
https://www.zhihu.com/zvideo/1992404547432370347/