The python nested closure decorator global, nonlocal keywords

Nesting: function defined functions within the 
closure: Open Closed Principle meet: add new features to function without modifying the source code is called the 

# Global global variables into local variables 
NUM = 100 DEF Fn1 ():
     Global NUM 
    NUM = 600
     return NUM
 Print (Fn1 ())   # 600 # nonlocal nested variables into local variables DEF Outer (): 
    NUM = 888
     def : Inner () 
        nonlocal NUM 
        NUM = 666
         Print (NUM)   # 666     Inner ()
     Print (NUM)   # 666 Outer () # decorator 
# to add new features without changing the source code under the circumstances def











Outer (FUNC):
     DEF Inner (* args, ** kwargs):
         # pass # new features 
        RES = FUNC (* args, ** kwargs)    # decompression bring original function 
        Pass  # new function 
        return RES
     return Inner
 # decorator (outer), to give a new function (Inner) 
@outer
 DEF Fn ():
     Pass 

RES = Fn ()
 Print (RES) 

DEF foo (Fn):
     # define a nested function 
    DEF bar (a): 
        Fn (a * ( A -. 1 ))
         Print ( " * " * 15,)
         Return Fn (A * (A -. 1 )) 

    return bar 


'' ' 
below the decorative effect is equivalent to: foo (my_test), 
my_test will replace (decorative) to return the value of the statement; 
Since foo () function returns the bar function, so my_test bar is 
at the same time, a parameter corresponding to the bar my_test function parameters a 
'' ' 


@foo 
DEF my_test (a):
     Print ( " == my_test function == " , a) 


# print my_test function, see It is actually a bar function 
Print (my_test, 1111111 )
 # The following code looks calling my_test (), in fact, is to call bar () function 
my_test (10)