Python 异常之后不知多少行的解决办法

淩亂°似流年 2022-09-23 05:55 99阅读 0赞

**一、说明：**

用try except之后，抛出的错误却不知道第几行，有时候着实让人着急

解决这个办法要使用 tracebak 来跟踪错误

常见如下

<table style="border:0px; margin:0px; padding:0px; vertical-align:baseline; border-collapse:collapse; border-spacing:0px; line-height:1.4em; background:transparent"> 
 <tbody style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; background:transparent"> 
  <tr style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; background:transparent"> 
   <td style="font-family:Monaco,&quot;Lucida Console&quot;,monospace; border-top-width:0px; border-bottom-width:0px; border-left-width:0px; margin:0px; padding:5px; vertical-align:baseline; line-height:1.4em; white-space:nowrap; overflow-x:auto; overflow-y:hidden; text-align:right; color:rgb(136,136,136); border-right-width:3px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; background:rgb(231,229,220)"> 
    <div style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; width:23px; background:transparent"> 
     <span style="font-size:18px">1<br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> 2<br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> 3<br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> 4<br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> </span> 
    </div> </td> 
   <td style="font-family:Monaco,&quot;Lucida Console&quot;,monospace; border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; white-space:nowrap; overflow-x:auto; overflow-y:hidden; background:transparent"> 
    <div style="border:0px; margin:0px; padding:5px; vertical-align:baseline; line-height:1.4em"> 
     <span style="font-size:18px">try<span style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; background:transparent">:</span><br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> &nbsp; &nbsp;&nbsp;<span style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; color:rgb(0,102,153); background:transparent">print</span>&nbsp;dddd<br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> except Exception<span style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; background:transparent">,</span>&nbsp;e<span style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; background:transparent">:</span><br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> &nbsp; &nbsp;&nbsp;<span style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; color:rgb(0,102,153); background:transparent">print</span>&nbsp;e</span> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

这样子的代码只是输出了错误的主要信息，并没有输出你错误的地点

使用tracebak  ( import tracebak )

<table style="border:0px; margin:0px; padding:0px; vertical-align:baseline; border-collapse:collapse; border-spacing:0px; line-height:1.4em; background:transparent"> 
 <tbody style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; background:transparent"> 
  <tr style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; background:transparent"> 
   <td style="font-family:Monaco,&quot;Lucida Console&quot;,monospace; border-top-width:0px; border-bottom-width:0px; border-left-width:0px; margin:0px; padding:5px; vertical-align:baseline; line-height:1.4em; white-space:nowrap; overflow-x:auto; overflow-y:hidden; text-align:right; color:rgb(136,136,136); border-right-width:3px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; background:rgb(231,229,220)"> 
    <div style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; width:23px; background:transparent"> 
     <span style="font-size:18px">1<br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> 2<br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> 3<br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> 4<br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> </span> 
    </div> </td> 
   <td style="font-family:Monaco,&quot;Lucida Console&quot;,monospace; border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; white-space:nowrap; overflow-x:auto; overflow-y:hidden; background:transparent"> 
    <div style="border:0px; margin:0px; padding:5px; vertical-align:baseline; line-height:1.4em"> 
     <span style="font-size:18px">try<span style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; background:transparent">:</span><br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> &nbsp; &nbsp;&nbsp;<span style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; color:rgb(0,102,153); background:transparent">print</span>&nbsp;dddd<br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> except Exception<span style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; background:transparent">,</span>&nbsp;e<span style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; background:transparent">:</span><br style="border:0px; margin:0px; padding:0px; line-height:1.4em"> &nbsp; &nbsp; traceback<span style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; background:transparent">.</span>print_exc<span style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; background:transparent">(</span><span style="border:0px; margin:0px; padding:0px; vertical-align:baseline; line-height:1.4em; background:transparent">)</span></span> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

这样就能够知道代码错误到底在第几行，以便于我们修改错误。

**二、例子：**

test1.py中，当分母为0的时候，调用系统退出

**\[python\] [view plain][] [copy][view plain]**

1.  **\#!/usr/bin/python  **
2.  **import sys  **
3.  **def division(a=1, b=1):  **
4.  **    if b==0:  **
5.  **         print 'b eq 0'  **
6.  **         sys.exit(1)  **
7.  **    else:  **
8.  **         return**** a/b **

test2.py中，用try..except捕获异常，然后traceback.print\_exc()打印。

**\[python\] [view plain][] [copy][view plain]**

1.  **\#!/usr/bin/python  **
2.  **import sys  **
3.  **import traceback  **
4.  **import test1   **
5.  **   **
6.  **a=10  **
7.  **b=0  **
8.  **   **
9.  **try:  **
10. **    print test1.division(a,b)  **
11. **except:  **
12. **    print 'invoking division failed.'  **
13. **    traceback.print\_exc()  **
14. **    sys.exit(1)  **

test1.py中，当分母为0的时候，调用系统退出

**\[python\]**  [view plain][]   [copy][view plain]

1.  \#!/usr/bin/python  
2.  **import** sys  
3.  **def** division(a=1, b=1):  
4.      **if** b==0:  
5.           **print** 'b eq 0'  
6.           sys.exit(1)  
7.      **else**:  
8.           **return** a/b

test2.py中，用try..except捕获异常，然后traceback.print\_exc()打印。

**\[python\]**  [view plain][]   [copy][view plain]

1.  \#!/usr/bin/python  
2.  **import** sys  
3.  **import** traceback  
4.  **import** test1   
5.     
6.  a=10  
7.  b=0  
8.     
9.  **try**:  
10.     **print** test1.division(a,b)  
11. **except**:  
12.     **print** 'invoking division failed.'  
13.     traceback.print\_exc()  
14.     sys.exit(1)

执行test2.py失败抛出异常。

$python test2.py  
execution python-2.5.1/python (enodeb/linux)  
**b eq 0  
invoking division failed.  
Traceback (most recent call last):  
  File "test2.py", line 10, in <module>  
    test1.division(a,b)  
  File "/home/fesu/test1.py", line 6, in division  
    sys.exit(1)  
SystemExit: 1**

[view plain]: http://blog.csdn.net/ace_fei/article/details/7790274#