裝飾器相當于一個裝飾，不修改函數(shù)原本內(nèi)容，只是增添內(nèi)容

def my_decorator(func):
    def warpper():
        print("有函數(shù)要執(zhí)行了")
        func()
        print("有函數(shù)執(zhí)行完畢")

    return warpper

@my_decorator
def say_hello():
    print("hello")


say_hello()

相當于

def my_decorator(func):
    def warpper():
        print("有函數(shù)要執(zhí)行了")
        func()
        print("有函數(shù)執(zhí)行完畢")

    return warpper


def say_hello():
    print("hello")


my_decorator(say_hello)()