Maybe you know Design Pattern, then you don’t feel unfamiliar with decorator pattern. decorator in python is just similar to the thought.

decorator pattern is such a structure that you can extend the function of a class and don’t need to inherit from it.

You also need to know what’s closure:
‘The criteria that must be met to create closure in Python are summarized in the following points.

• We must have a nested function (function inside a function).
• The nested function must refer to a value defined in the enclosing function.
• The enclosing function must return the nested function.’
  ‘Closures can avoid the use of global values and provides some form of data hiding. It can also provide an object oriented solution to the problem.’

‘Functions and methods are called callable as they can be called.
In fact, any object which implements the special method call() is termed callable. So, in the most basic sense, a decorator is a callable that returns a callable.’

Decorator Implementation

Python Built-in Decorators

@property

def ():
    doc = "The  property."
    def fget(self):
        return self._value
    def fset(self, value):
        self._value = value
    def fdel(self):
        del self._value
    return locals()
foo = property(**(foo))

class A(object):
  def __init__(self):
    self._v = 0
    self.cc = 1


  def v(self):
    return self._v

  
  @v.setter
  def v(self, v):
    self._v = v
    self.cc = self._v / 10

@classmethod & @staticmethod

• Python装饰器的前世今生
• decorator