python 面向对象（三）magic methods

magic methods就是双下划线方法

As a Python developer who wants to harness the power of object-oriented programming, you’ll love to learn how to customize your classes using special methods, also known as magic methods or dunder methods. A special method is a method whose name starts and ends with a double underscore. These methods have special meanings for Python.

再谈(reprise) 三种下划线

1. 单下划线在前一般用于声明私有成员，比如 _private_var
2. 单下划线在后一般用于命名已经被保留关键字占用的变量，比如 class_,type_
3. 双下划线一般被用于 Python 内置的特殊方法或者属性，比如 name,file，有时候也被称之为魔方方法。

Table of Contents

参考Python's Magic Methods: Leverage Their Power in Your Classes

• Getting to Know Python’s Magic or Special Methods
• Controlling the Object Creation Process
• Representing Objects as Strings
• Supporting Operator Overloading in Custom Classes
• Introspecting Your Objects
• Controlling Attribute Access
• Managing Attributes Through Descriptors
• Supporting Iteration With Iterators and Iterables
• Making Your Objects Callable
• Implementing Custom Sequences and Mappings
• Handling Setup and Teardown With Context Managers
• Conclusion

Reference

1. Python's Magic Methods: Leverage Their Power in Your Classes
2. Python中的下划线和魔方方法
3. What is the meaning of single and double underscore before an object name?