day 23 for members of nested classes and objects

1, members of the class? Variables, methods, properties

　　Variable: 1, instance variables (field)

　　　　     2, class variables (static field)

　　Method: 1, examples of method  

　　　　    2, static methods

@staticmethod static method, if the method does not require the use of encapsulated object values, then you can use the static method @staticmethod, in front of the function defined 
def display (a1, a2):

 　　　　    3, class methods @classmethod

　　Properties: transformation out by methods

2, the difference between static methods, class methods and instance methods?

　　Definition of when a static method, class method definitions need to add @, add an instance method does not require
　　the implementation of static methods, class methods performed by the class can be called directly, instantiate an instance method first, and then through the object. Calling
　　scenarios?
　　　　If the relevant data will not be used within the method of the object, and can be static class
　　　　Examples of the method if the object need to use
　　　　if the code will be used in the current class, class methods can be used in order to save

3, attributes:

Summary property

4、