python 魔法方法加减乘除

加减乘除"/>

python 魔法方法加减乘除

一、算术魔法方法的举例

1、加法(__add__)的算术运算调用减法(__sub__)的算术运算，减法(__sub__)的算术运算调用加法(__add__)的算术运算

class New_Init(int):

def __add__(self,other):return int.__sub__(self,other)

def __sub__(self,other):return int.__add__(self,other)>>> a = New_Init('5')>>> b = New_Init(6)>>> a+b-1

>>> a-b11

>>>

2、针对以上需求，现在要求不使用int方法进行运算

classTry_int(int):def __add__(self,other):return self+otherdef __sub__(self,other):return self+other>>> a = Try_int(5)>>> b = Try_int(6)>>> a+b

Traceback (most recent call last):

File"", line 1, in a+b

File"/Users/wufq/Desktop/加法算术运算.py", line 3, in __add__

return self+other

File"/Users/wufq/Desktop/加法算术运算.py", line 3, in __add__

return self+other

File"/Users/wufq/Desktop/加法算术运算.py", line 3, in __add__

return self+other

[Previous line repeated990more times]

RecursionError: maximum recursion depth exceeded#不使用int会使程序一直进行递归运算，导致内存不足

#程序改进

classTry_int(int):def __add__(self,other):return int(self)+int(other)def __sub__(self,othe