Python class definition examples of notes

First, class definition:

Class < category name:

< statements >

Once instantiated, you can use its properties, and in fact, after you create a class, you can access its properties through the class name

If you modify its properties directly using the class name, it will directly affect the object that has already been instantiated

The principles of the definition of the Python class

attribute has no public or private claim.

There is no construction method, and the initial method is only the method that is executed when instantiated.
The method must be defined with the self argument, similar to this in Java.

The Python language is more flexible.

users.py file

The code is as follows	Copy Code
#!/usr/bin/env python #-*-Encoding:utf-8-*- Class User (object): "This is a user class" Name = "Tomas" Age = 0 def __init__ (self,age=22): Self.age = Age def showage (self): Print Self.age def showclassname (self): Print self.__class__.__name__ def showclassdoc (self): Print Self.__class__.__doc__users

2.py file

The code is as follows	Copy Code
#!/usr/bin/env python #-*-Encoding:utf-8-*- Import Users user = Users.user () User.showage () User.showclassname () User.showclassdoc ()

If you can call this class in users.py,

The code is as follows	Copy Code
user = User ()

The following summary

Private properties of the class:

__private_attrs a two underscore, declaring that the property is private and cannot be used or accessed directly outside the class

When used in methods inside a class Self.__private_attrs

Methods of the class

Within the class, use the DEF keyword to define a method for the class, unlike a generic function definition, the class method must contain the parameter self and the first argument

Private class method

__private_method The two underscore, declares the method as private and cannot be invoked outside the class

Calling Slef.__private_methods inside a class

The proprietary method of the class:

__init__ constructor, called when the object is generated

__del__ destructor, use when releasing objects

__repr__ Printing, converting

__SETITEM__ is assigned by index

__GETITEM__ Get values by index

__len__ Get length

__CMP__ comparison operations

__call__ function call

__add__ addition operation

__sub__ Subtraction Operation

__mul__ multiplication operation

__DIV__ in addition to operations

__MOD__ calculation

__pow__ said the Square