异常处理

参考链接：http://developer.51cto.com/art/200902/111535.htm

1. 常用的异常处理
   
   

   try:
           a = b
           b = c
       except Exception,data:
           print Exception,":",data
       '''输出：＜type 'exceptions.Exception'＞ : local variable 'b' 
   referenced before assignment ''

   
   
   
   
2. trackbak
   
   

   try:
       a = b
       b = c
   except:
       print traceback.print_exc()
       '''输出： Traceback (most recent call last):
       File "test.py", line 20, in main
       a = b
       UnboundLocalError: local variable 'b' referenced before assignmen

   
   
   
   
3. 其他