annotate a traceback

[Robin Becker]

I want to annotate a traceback in routine A which is raised in B. Useful 
information in A is not available in B

I propose to use something like

def A(info):
     try:
         B()
     except:
         t,v,b=sys.exc_info()
         v.args = (' '.join(map(str,v.args))+', info=%r' % info,)
         raise

is this a reasonable approach?
-- 
Robin Becker