python中抽象类的实现

from abc import ABC, abstractmethod

class Animal(ABC):  # 继承 ABC，表示这是一个抽象类
    @abstractmethod
    def speak(self):
        """子类必须实现这个方法"""
        pass

# animal = Animal()  # TypeError: 不能实例化抽象类

class Dog(Animal):
    def speak(self):  # 必须实现抽象方法
        print("Woof!")

dog = Dog()
dog.speak()  # Woof!

from abc import ABC, abstractmethod

class Shape(ABC):
    @abstractmethod
    def area(self):
        """计算面积"""
        pass

    @abstractmethod
    def perimeter(self):
        """计算周长"""
        pass

    def describe(self):
        """普通方法，子类可直接使用"""
        print(f"这是一个图形，面积: {self.area()}, 周长: {self.perimeter()}")

from abc import ABC, abstractmethod

class Employee(ABC):
    @property
    @abstractmethod
    def salary(self):
        """子类必须实现 salary 属性"""
        pass

class FullTimeEmployee(Employee):
    def __init__(self, monthly_salary):
        self._monthly_salary = monthly_salary

    @property
    def salary(self):
        return self._monthly_salary

emp = FullTimeEmployee(10000)
print(emp.salary)  # 10000

class Rectangle(Shape):
    def __init__(self, width, height):
        self.width = width
        self.height = height

    def area(self):
        return self.width * self.height

    # 忘记实现 perimeter 方法

# rect = Rectangle(3, 4)  # TypeError: 不能实例化抽象类 Rectangle