Python装饰器类方法扩展元类管理实例探究

def my_decorator(func):
    def wrapper():
        print("Something is happening before the function is called.")
        func()
        print("Something is happening after the function is called.")
    return wrapper

@my_decorator
def say_hello():
    print("Hello!")

say_hello()

def decorator_one(func):
    def wrapper():
        print("Decorator One - Before")
        func()
        print("Decorator One - After")
    return wrapper

def decorator_two(func):
    def wrapper():
        print("Decorator Two - Before")
        func()
        print("Decorator Two - After")
    return wrapper

@decorator_one
@decorator_two
def say_hello():
    print("Hello!")

say_hello()

def parametrized_decorator(param):
    def real_decorator(func):
        def wrapper(*args, **kwargs):
            print(f"Decorator parameter: {param}")
            func(*args, **kwargs)
        return wrapper
    return real_decorator

@parametrized_decorator("Custom Param")
def greet(name):
    print(f"Hello, {name}!")

greet("Alice")

class MyClass:
    @classmethod
    def my_class_method(cls):
        print("This is a class method.")

def extend_class_method(func):
    def wrapper():
        print("Do something before executing the method.")
        func()
        print("Do something after executing the method.")
    return wrapper

# Applying decorator to a class method
MyClass.my_class_method = extend_class_method(MyClass.my_class_method)

class MyClass:
    @classmethod
    def my_class_method(cls):
        print("This is a class method.")

def extend_class_method(func):
    def wrapper():
        print("Do something before executing the method.")
        func()
        print("Do something after executing the method.")
    return wrapper

# Applying decorator to a class method
MyClass.my_class_method = extend_class_method(MyClass.my_class_method)
MyClass.my_class_method()

class Meta(type):
    def __new__(cls, name, bases, dct):
        # Modify or enhance class behavior before it's created
        return super().__new__(cls, name, bases, dct)

class MyClass(metaclass=Meta):
    def my_method(self):
        print("This is a method inside MyClass.")