The closure python decorator +

Closure

Internal function references to external function scope variables.

Property within the function are all life-cycle, during the execution of all the functions

Closure function in the variable privatized closure, similar to object-oriented

Pictures resolve

Examples of a

https://www.bilibili.com/video/av18586448/?spm_id_from=333.788.videocard.16

DEF FUNC (): # external function 
    A. 1 =   # external function scope variables 
    Print ( " the this IS FUNC. " )
     DEF func1 (NUM): # internal function is actually a closure function 
        Print ( " the this IS func1 " )
         Print (NUM + a)
     return func1 # function saves the variables a 
 # func () running external functions, internal function was created 
var = func () # creation process during the execution of func function in 
# var == func1 
var (. 3) # when del var a not exist

Example Two

mylist=[1,2,3,4,5]
def func(obj):
    print('func:',obj)
    def func1():
        obj[0]+=1
        print('func1',obj)
    return func1
var=func(mylist)
#var:obj,print('func1',obj)

Decorator

Decorator syntax sugar @
@ func1
DEF FUNC ():
    Print ( 'aaa')
    does not affect the function of the original function, but also add new features
    > @ func1
    > DEF the myPrint () ():
    the myPrint () () == func2 ( ) + myprint ()
    normal decorator zsq (bzs) ()
    decorator function parameters: dczsq (cs = 'man' ) (bza) ()
                     multi-layer packaging the parameters to receive the decoration
    are decorated function parameters: just innermost function parameters can be passed

Examples of a

DEF arg_fun (Sex)
     DEF FUNC (b_func):
         DEF func2 ()
          IF Sex == ' man ' :
             Print ( ' you can not have baby ' )
          IF Sex == ' Woman ' :
             Print ( ' You can have baby ' ) 

         return b_func ()
         return func2
     return fun1 

# arg_func (Sex = 'man') () ()> func1 
# func1 ()> func2 
# func2 ()> ( '' you can not have baby '') or ( 'you can Health doll ') 

Arg_fun @ () 
DEF   man ():
     Print ( ' good work ' ) 
@ arg_fun () 
DEF   Woman ():
     Print ( ' good work ' ) 


man () 
Woman ()

Example Two

def func1(func)
      def func2(x,y)
            print(x,y)
            x+=5
            y+=5
            return func(x,y)
       return func2
@func1
def mysum(a,b)
      print(a+b)
mysum(1,2)

Example Three

import time
def display_time(func):
    def wrapper(*args):
        t1=time.time()
        result=func(*args)
        t2=time.time()
        print("Total time:{:.4} s".format(t2-t1))
        return result
    return wrapper
def is_prime(num)
    if num<2:
        return False:
    elif num==2:
        return True
    else:
        for i in range(2,num):
            if num%i==0:
                return False
        return True
@display_time
def count_prime_nums(maxnum):
    count=0
    for i in range(2,maxnum):
        if is_prime(i):
            count=count+1
    return count
count=count_prime_nums(10000)
print(count)