python修饰器的实例代码

以下是一个简单的 Python 修饰器的示例代码:

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_whee():
    print("Whee!")

say_whee()

输出:

Something is happening before the function is called.
Whee!
Something is happening after the function is called.

该示例中，我们定义了一个名为 `my_decorator` 的修饰器函数，它接受一个函数作为参数，并返回一个新函数 (即包装器函数)。我们使用 `@my_decorator` 装饰器语法在 `say_whee` 函数上应用了该修饰器，这样在调用 `say_whee` 时，它会先输出 "Something is happening before the function is called."，然后调用 `say_whee` 函数本身，最后输出 "Something is happening after the function is called."。