nested exceptions dilemma

[Jason R. Mastaler]

Greetings,

I'm trying to write a "wrapper" script whose purpose is to execute a
more complex Python script, catch all exceptions that it might
generate, and then log the corresponding tracebacks.

It should first try to log to file ~/tmda.debug.  If any exceptions
occur while trying that, it attempts to instead log to
~/CATASTROPHIC_FAILURE.  If any exceptions occur while trying that,
the script prints the traceback to stdout before giving up.

Here is a simplified example of the wrapper:

---- start ----

#!/usr/bin/env python
try:
    import os
    import sys
    import traceback
    execfile('tmda-filter')
except:
    try:
        fp = open(os.path.expanduser('~/tmda.debug'))
        traceback.print_exc(file=fp)
    except:
        try:
            fp = open(os.path.expanduser('~/CATASTROPHIC_FAILURE'))
            traceback.print_exc(file=fp)
        except:
            traceback.print_exc(file=sys.stdout)

---- end ----

The problem I'm having is that traceback.print_exc only prints the
traceback from the most recently raised exception.  For example, if
the write to "~/tmda.debug" raises an IOError exception, the traceback
that ends up in ~/CATASTROPHIC_FAILURE only shows that and has no
mention of why the execfile failed.

Instead, I'd like to include the entire chain of exceptions in the
traceback.  Does anyone have any suggestions on how to accomplish
this?

Thanks.

-- 
(TMDA - http://tmda.sourceforge.net)
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