Exceptions: Logging TB and local variables?

[allen.fowler]

> Two possibilieies:
>
> You will need to determine ALL the exceptions that the 3rd party party modules
> can raise.  If they are custom exceptions you will need to import them into your
> application from their modules.
>
> example:
>
> say that 3rd party modules raise TransientError, IOError, and ValueError
> exceptions.  TransientError is a custom exception from module foo
>
> from foo import TransientError
>
> for item in bigset:
>    try:
>      self.__sub1(item)
>      self.__sub2(item)
>      self.__sub3(item)
>    except (TransientError, IOError, ValueError):
>      # Log error and continue to next item in set.
>      log_error_to_file()
>
> 2) Hook exception traceback handler
>
> def myTraceBackHandler(type, value,tb):
>      global <variables I want to dump during traceback>
>      #
>      # This function allows the user to redefine what happens if the program
>      # aborts due to an uncaught exception.
>      # This provides a way to get a "partial" session log if the program
>      # aborts"as well as some information about what caused the program to
>      # abort.
>      #
>      import traceback
>      #
>      # Get traceback lines
>      #
>      tblines=traceback.format_exception(type, value,tb)
>      #
>      # Write some lines to log
>      #
>      log_error_to_file()
>      #
>      # Always write the exceptions to screen
>      #
>      sys.exit('\n'.join(tblines))
>
> Hope this helps.
>
> -Larry

This looks interesting...

What is myTraceBackHandler?  Is it some sort of event handler? Can you
clarify?

Thanks,
Allen