Python 面向对象编程

理解类、对象、属性、方法、构造函数、继承、封装和多态。

1. 类和对象

class Student:
    pass

stu = Student()
print(stu)

2. 属性和方法

class Student:
    def say_hello(self):
        print("你好，我是学生")

stu = Student()
stu.say_hello()

3. 构造函数

class Student:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def introduce(self):
        print(f"我叫{self.name}，今年{self.age}岁")

4. 类属性

class Student:
    school = "第一中学"

    def __init__(self, name):
        self.name = name

5. 封装

class Account:
    def __init__(self, balance):
        self.__balance = balance

    def get_balance(self):
        return self.__balance

6. 继承和方法重写

class Animal:
    def speak(self):
        print("动物在叫")

class Cat(Animal):
    def speak(self):
        print("喵喵")

7. 多态

def make_sound(animal):
    animal.speak()

make_sound(Cat())

本章总结

类是对象的模板，对象是类的实例。封装保护内部数据，继承复用代码，多态让程序更灵活。