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+# 第5章 面向对象编程（OOP）
+
+## 5.1 面向对象概述
+
+- **类（Class）**：抽象模板，定义属性和方法
+- **对象（Object）**：类的实例
+- **封装**：隐藏内部实现细节
+- **继承**：子类继承父类的属性和方法
+- **多态**：同一接口，不同实现
+
+---
+
+## 5.2 类和对象
+
+```python
+class Dog:
+    species = "犬科"
+
+    def __init__(self, name, age):
+        self.name = name
+        self.age = age
+
+    def bark(self):
+        return f"{self.name} 汪汪叫！"
+
+    def __str__(self):
+        return f"{self.name}（{self.age}岁）"
+
+my_dog = Dog("旺财", 3)
+print(my_dog.bark())
+print(my_dog)
+```
+
+---
+
+## 5.3 封装
+
+```python
+class BankAccount:
+    def __init__(self, owner, balance=0):
+        self.owner = owner
+        self.__balance = balance
+
+    def deposit(self, amount):
+        if amount > 0:
+            self.__balance += amount
+
+    def get_balance(self):
+        return self.__balance
+```
+
+---
+
+## 5.4 继承
+
+```python
+class Animal:
+    def __init__(self, name):
+        self.name = name
+
+class Cat(Animal):
+    def speak(self):
+        return f"{self.name} 喵喵叫"
+
+class Dog(Animal):
+    def speak(self):
+        return f"{self.name} 汪汪叫"
+```
+
+---
+
+## 5.5 魔术方法
+
+```python
+class Book:
+    def __init__(self, title, author, price):
+        self.title = title
+        self.author = author
+        self.price = price
+
+    def __str__(self):
+        return f"《{self.title}》 - {self.author}"
+
+    def __repr__(self):
+        return f"Book('{self.title}', '{self.author}', {self.price})"
+
+    def __eq__(self, other):
+        if isinstance(other, Book):
+            return self.title == other.title
+        return False
+```
+
+---
+
+## 本章练习
+
+1. 设计一个 `Student` 类，包含姓名、年龄、成绩属性
+2. 使用继承创建 `Animal` 类及其子类
+3. 实现一个单例模式的配置管理器类