Python's Decorator

The role of adorners: To add functionality without changing the source code and the calling method

(i) the base adorner (only implemented as function add function)

Feature implementation:

Add the ability to calculate run time for the original function

" "High -order function + nested function = Adorner Adorner principle: (1) cannot change the source code of the decorated function (2) cannot change the method of calling the decorated function" "Import TimedefTimer (func):defFunc_deco (*args,**Kwargs): Start_time=time.time () func (*args,**Kwargs) Run_time=time.time ()-start_timePrint("function run time is%s"%run_time)returnFunc_deco#returns the memory address of the function run@timerdefFun_te (name,age): Time.sleep (1)    Print(name)Print(age) Fun_te ('Lihanyu', 18)

The test results are as follows:

(ii) Adorner climax version

The scenario is implemented as follows: During the login process of the website, part is local log on, part is LDAP login, after the login method is determined, the user login function is realized.

Importtimeuser,pwd=('Lihanyu',' the')defout (auth_type):defAuth (func):defWapper (*args,**kwargs):#can implement arbitrary number of parameters            ifauth_type=='Local': Username=input ("Username:") Password=input ("Password:")                ifUsername==user andpassword==pwd:Print("Validation Successful") Res=func (*args,**Kwargs)returnRes#Returns the return value of the running function, which is the return value of home ()                Else:                    Print("user name or password input error")            elifauth_type=='LDAP':                Print("I don't know ... ")            Else:                Print("no such sign-in method")        returnWapperreturnAuthdefindex ():Print("Welcome to Index") @out (Auth_type='Local')defHome ():Print('Welcome to Home Page')    return "From home"@out (Auth_type='LDAP')defBBS ():Print("Welcome to BBS") index ()Print(Home ()) BBS ()

The test results are as follows:

Welcome to the Great God test, correct me, thank you!

Python's Decorator