Python interior decorator (property/staticmethod/classmethod)

Python built-in property, Staticmethod, Classmethod three adorners, sometimes we also use, here is a simple explanation

1. Property

Function: As the name implies, decorate functions as attributes

In general, we call class method members, which are written as follows:

Class PropertyTest ():    def __init__ (self,x,y):        self.x = x        self.y = y    def square (self):        return self.x * Self.ypt = propertytest (3,5) print (Pt.square ())

Here's a look at square as a method of the class, but if it is written in the following form, then it is not certain that the invocation must be a class method:

Class PropertyTest ():    def __init__ (self,x,y):        self.x = x        self.y = y    @property    def square (self):        return self.x * self.ypt = propertytest (3,5) print (Pt.square)

The calling method here is similar to calling a member variable, and if written as print (Pt.square ()) the compiler will error

This is the use of the property, to change a method into a variable to invoke

2, Staticmethod

Function: The method in the class can be called directly without instantiation, as shown below

Class A ():    def __init__ (self):        pass    @staticmethod    def plus (x, y):        print (x*y) c = A () c.plus (2,3) A.plus (4,5)

We can instantiate class A and then call the method plus or directly class. Method call

3, Classmethod

Function: Similar to Staticmethod, the difference is that the calling class is passed in as the first parameter, as follows:

Class A ():    def __init__ (self):        pass    @classmethod    def Plus (cls,x,y):        print (CLS)        print (x*y ) A.plus (4,5) c = A () c.plus (5,6)

Here print (CLS) prints Class A, other usages are the same as Staticmethod

Python interior decorator (property/staticmethod/classmethod)