from abc import ABC, abstractmethod
class Animal(ABC):
@abstractmethod
def speak(self):
pass
@abstractmethod
def move(self):
    pass
下面这行会报错：TypeError: Can't instantiate abstract class...
a = Animal()
class Dog(Animal):
def speak(self):
return "Woof!"
def move(self):
return "Run"
d = Dog()  # ✅ 正常创建
print(d.speak())  # Woof!

class Shape(ABC):
    @abstractmethod
    def area(self):
        raise NotImplementedError("子类必须实现 area 方法")

class Vehicle(ABC):
    brand = "Unknown"  # 类属性
def __init__(self, name):
    self.name = name  # 实例属性

def start_engine(self):  # 普通实例方法
    print(f"{self.name} engine started.")

@staticmethod
def honk():
    return "Beep!"

@abstractmethod
def drive(self):
    pass
class Car(Vehicle):
def drive(self):
return f"{self.name} is driving on road."
c = Car("Tesla")
c.start_engine()  # ✅ 继承自父类
print(c.honk())    # ✅ 静态方法也可调用
print(c.drive())   # ✅ 实现了抽象方法

from abc import ABC, abstractmethod
class A(ABC):
@abstractmethod
def foo(self): ...
class B(A):
def foo(self): ...
print(A.abstractmethods)  # frozenset({'foo'})
print(B.abstractmethods)  # frozenset()