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