Python 3.x--Decorator

———————— adorner = higher order function + nested function ——————————

High order function: 1, pass a function name as an argument to another function, 2, the return value contains the function name

Def func1 ():
    Print ("This is Func1")

def test (func):
    Print (func)
    Func ()

Test (FUNC1)

Output Result:

Adorner: Add additional functions to other functions without changing the original function code and calling method

Import time

def bar ():
    Time.sleep (2)
    Print ("This is Bar")

def test1 (func1):
    Print (FUNC1)
    Return func1

Bar = test1 (bar)
Bar ()

Does not change the calling method, no new features are added---------

Import time
def deco (func):
    Start_time = Time.time ()
    Return  func
    Stop_time = Time.time ()
    Print (' Running time is%s: '% (stop_time-start_time))

def test1 ():
    Time.sleep (2)
    Print ("This is Test1")
Def test2 ():
    Time.sleep (2)
    Print ("This is Test2")

Test1 = Deco (test1)
Test1 ()
Test2 = Deco (test2)
Test2 ()

Operation Result:

Add new features without changing the calling method---------

Import time
def timer (func):
    Def deco ():
        Start_time = Time.time ()
        Func ()
        Stop_time = Time.time ()
        Print (' Running time is%s: '% (stop_time-start_time))
    Return deco

def test1 ():
    Time.sleep (2)
    Print ("This is Test1")
Def test2 ():
    Time.sleep (3)
    Print ("This is Test2")

Test1 = Timer (test1)
Test1 ()
Test2 = Timer (test2)
Test2 ()

Operation Result:

Use the @ symbol-----------

Import time
def timer (func):
    Def deco ():
        Start_time = Time.time ()
        Func ()
        Stop_time = Time.time ()
        Print (' Running time is%s: '% (stop_time-start_time))
    Return deco
@timer
def test1 ():
    Time.sleep (2)
    Print ("This is Test1")
Def test2 ():
    Time.sleep (3)
    Print ("This is Test2")

Test1 ()
Test2 = Timer (test2)
Test2 ()

The original function has parameter-----------

Import time
def timer (func):
    def deco (*arg,**kwarg):
        Start_time = Time.time ()
        Func (*arg,**kwarg)
        Stop_time = Time.time ()
        Print (' Running time is%s: '% (stop_time-start_time))
    Return deco
@timer
def test1 ():
    Time.sleep (2)
    Print ("This is Test1")
@timer  #test2 = Timer (test2)
def test2 (name,age):
    Time.sleep (1)
    Print ("This is test2:", Name,age)

Test1 ()
Test2 (' Lili ', 18)

Operation Result:

The original function has a return value----------

user,passwd = ' Lili ', ' abc '
def auth (func):
    def wrapper (*args,**kwargs):
        Username = input ("username:"). Strip ()
        Password = input ("PASSWD:"). Strip ()

        If user = = Username and passwd ==password:
            Print ("\033[32;1muser has passed authenticatiom\033[0m")
            return func (*args,**kwargs)
        Else
            Exit ("\033[31;1minvalid username or password\033[0m")
    Return wrapper
@auth
Def Page1 ():
    Print ("This is Page1")
    Return "from Page1"
@auth
Def page2 ():
    Print ("This is Page2")
@auth
Def page3 ():
    Print ("This is Page3")


Print (Page1 ())

Operation Result:

Adorner with parameter-------------

 user,passwd = ' Lili ', ' abc ' 
 DEF Auth (auth_type): 
 Print ("Auth_arge:", Auth_type) 
 def outer_wrapper (func ): 
 def wrapper (*args,**kwargs): 
 If Auth_type = = ' P1 ': 
 Username = input ("Usern Ame: "). Strip () 
 Password = input (" PASSWD: "). Strip () 
 
 If user = = Username and PASSW D ==password: 
 Print ("\033[32;1muser has passed authenticatiom\033[0m") 
 Retur n func (*args,**kwargs) 
 Else: 
 Exit ("\033[31;1minvalid username or password\033[0m ") 
 elif Auth_type = = ' P2 ': 
 print (' P2 pass ') 
 return wrapper 
 Return Oute R_wrapper 
 
 @auth (auth_type = "P1") 
 Def Page1 (): 
 Print ("This is Page1") 
 return ' from Page1 ' 
 @auth (Auth_type = "P2") 
 def page2 (): 
 Print ("This is Page2") 
 
 Print (Page1 ()) 
 Page2 () 

Operation Result:

Python 3.x--Decorator