deco_demo.py

def decoratorFunction(func):
    print "In Decorator Before function call"
    def _fn():
        try:
            ret = func()
            return ret
        except IOError as e:
            print "I/O error"
            rollback()
        except ValueError as e:
            print "Value error"
            rollback2() 
    return _fn

def rollback():
    print "in rollback"

def rollback2():
    print "in rollback2"

@decoratorFunction
def functionAudience():
    print "Inside functionAudience"
    try:
        h = 1 / 1
    except Exception as e:
        print "inside zerodivision error 1"
        raise IOError()
    
    return  "Everything Went well"


if __name__ == '__main__':
    hi = functionAudience()
    import pdb;pdb.set_trace()
    print "This would never get called in exception situation"