I am quoting here because it includes a helpful link and useful tips:

Also see http://blog.ianbicking.org/2007/09/12/re-raising-exceptions/ for a good discussion on the different scenarios.

Regarding reraiser5(), See the specific discussion in the comments on this pattern. Couple of comments I have are:
- You wouldn’t want to just “pass”, you should at least the exception, e.g., traceback.print_exc()
- Sometimes you want to cleanup conditionally, only if the operation fails.
- During cleanup, it is better to be more broader in catching exceptions.

Here is an example that I posted at the other blog as well:

success = 0
try:
    do_db_operation()
    success = 1
finally:
    if not success:
        try:
            do_rollback()
        except (KeyboardInterrupt, SystemExit):
            raise
        except:
            logging.getLogger().exception("Exception in cleanup ignored due to a pending exception on stack")
    else:
        do_commit()