python try catch

捕獲異常的方式

 

方法一：捕獲全部的異常

1. try:
   

2. a = b

3. b = c

4. except Exception,data:

5. print Exception,":",data

6. '''輸出：＜type 'exceptions.Exception'＞ : local variable 'b'
   

7. referenced before assignment '

 

方法二：採用traceback模塊查看異常，須要導入traceback模塊，這個方法會打印出異常代碼的行號

1. try:
   

2. a = b

3. b = c

4. except:

5. print traceback.print_exc()

6. 
   

7. '''輸出： Traceback (most recent call last):
   

8. File "test.py", line 20, in main

9. a = b

10. UnboundLocalError: local variable 'b

 

方法三：採用sys模塊回溯最後的異常

1. try:
   

2. a = b

3. b = c

4. except:

5. info = sys.exc_info()

6. print info

7. print info[0]

8. print info[1]

9. 
   

10. '''輸出：
    

11. (＜type 'exceptions.UnboundLocalError'＞, UnboundLocalError("local
    

12. variable 'b' referenced before assignment",),
    

13. ＜traceback object at 0x00D243F0＞)

14. ＜type 'exceptions.UnboundLocalError'＞
    

15. local variable 'b' referenced before assignment
    

16. '''