str( )它让Python将非字符串值表示为字符串 


 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 
 4 age = 23
 5 message = "happy " + age +"rd birthday!"       #python无法识别age，所以执行结果报错
 6 
 7 print(message)
 8 
 9 执行结果为：
10 
11 C:\Users\tby\AppData\Local\Programs\Python\Python37\python.exe C:/py3/rumen_shijian/str().py
12 Traceback (most recent call last):
13   File "C:/py3/rumen_shijian/str().py", line 5, in <module>
14     message = "happy " + age +"rd birthday!"
15 TypeError: can only concatenate str (not "int") to str
16 
17 进程已结束,退出代码1

 

 

 

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 
 4 age = 23
 5 message = "happy " + str(age) +"rd birthday!"     #str()它让Python将非字符串值表示为字符串，所以能打印出age的值2和3
 6 
 7 print(message)
 8 
 9 
10 
11 执行结果为：
12 
13 
14 C:\Users\tby\AppData\Local\Programs\Python\Python37\python.exe C:/py3/rumen_shijian/str().py
15 happy 23rd birthday!
16 
17 进程已结束,退出代码0

 

posted on 2017-11-22 19:09  wl404  阅读(617)  评论(0)    收藏  举报

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