Introduction to Python (vi) understanding of adorners

A function of the adorner used to extend the function of the original function
Like what:

def helloWorld(fun)        def out()                print ("======start========")                fun()                print ("=====end======")        return out@helloWorlddef back ()        print ("let‘s go")back()

Operation Result:

======start========let‘s go=====end======

The br/>@ symbol is the syntactic sugar of the adorner, which is used when defining the function and avoids the assignment of the value again.

Run step def back () →return out→def out ()
Adorner with parameters:

def helloWorld(arg):        def out(fun):                def go():                        print ("======start========")                        fun()                        print ("=====end======")                return go               return out@helloWorld("will‘)def back ():        print ("let‘s go")back()

Operation Result:

======start========let‘s go=====end======

See the adorner comes in with a parameter, then the running process of this parameter will be run, the overall operation of the process

When a function is also involved with parameters:

def logging(taskname):    def wrapper(func):        def retu(*args, **wkargs):            # 函数通过装饰起参数给装饰器传送参数            print (‘before task‘,taskname)            # 装饰器传变量给函数            taskid = 1            summer, funcres = func(taskid, *args, **wkargs)            print (‘after task‘, taskid, summer)        return retu    return wrapper@logging("test")def testd(taskid):    print ("testd runing",taskid)    return "task summer success eg",[]testd()

Run the results and steps:

Introduction to Python (vi) understanding of adorners