Python 学习笔记 - 4.if 表达式

转载自：http://www.xwy2.com/article.asp?id=108

 

方式1

>>>>>> s = ""  
>>>>>> a = s or "not none"  
>>>>>> a  
'not none'  
  
>>>>>> s = None  
>>>>>> a = s or "not none"  
>>>>>> a  
'not none'  
  
>>>>>> s = "aa"  
>>>>>> a = s or "not none"  
>>>>>> a  
'aa'  

 

方式2

>>>>>> s = None  
>>>>>> a = "not null" if s == None else s  
>>>>>> a  
'not null'  
  
>>>>>> s = "aa"  
>>>>>> a = "not null" if s == None else s  
>>>>>> a  
'aa'