why logging re-raise my exception and can't be caught?

[daniel]

I use a simple program to illustrate the problem:

import logging

def foo() :
    raise ValueError("foo")

if __name__ == "__main__" :
    try :
        foo()
    except ValueError :
        logging.exception("caught here")  -- seems re-raise the
exception and can't be caught
        print "caught here" --- just works.

I'm expecting the exception to be caught silently, and print the msg to
some place, if I comment out the logging statement, it just works, but
now, the stack trace is printed as if the except statement was not
there!!

how could this happen, just weird.. can I make the logging module
behave as I expected?

tks in advance.

daniel