Traceback objects in python

Question

I was debugging my python script and came across traceback<\/code> object, which is present at 2nd index in result, returned by sys.exc_info()<\/code> function. However, I tried to google out information related to traceback<\/code> object, but everywhere i got link to traceback module<\/code> in standard python lib. Then, I tried doing dir()<\/code> on traceback object, which gives me a list of attributes. In that list, following attributes looks interesting :-

 1. tb_frame,
 2. tb_lasti,
 3. tb_lineno,
 4. tb_next

Answer 1

As specified by in docpage specified by @vaultah,

These all are special read-only attributes.

1. tb_next is the next level in the stack trace (towards the frame where the exception occurred), or None if there is no next level;
2. tb_frame points to the execution frame of the current level;
3. tb_lineno gives the line number where the exception occurred;
4. tb_lasti indicates the precise instruction.

Note :- The line number and last instruction in the traceback may differ from the line number of its frame object if the exception occurred in a try statement with no matching except clause or with a finally clause.