Exception Messages

[Wanderer]

On Monday, October 15, 2012 1:34:24 PM UTC-4, MRAB wrote:
> On 2012-10-15 18:18, Wanderer wrote:
> 
> > On Monday, October 15, 2012 12:34:53 PM UTC-4, MRAB wrote:
> 
> >
> 
> >>
> 
> >> Yes, but you've put the message in msg, and Exception doesn't have that
> 
> >>
> 
> >> attribute.
> 
> >>
> 
> >
> 
> > That's weird. I got this Exception class definition idea from this post by Guido van Rostrum, Where he gives this main function to look like
> 
> >
> 
> > import sys
> 
> > import getopt
> 
> >
> 
> > class Usage(Exception):
> 
> >      def __init__(self, msg):
> 
> >          self.msg = msg
> 
> >
> 
> > def main(argv=None):
> 
> >      if argv is None:
> 
> >          argv = sys.argv
> 
> >      try:
> 
> >          try:
> 
> >              opts, args = getopt.getopt(argv[1:], "h", ["help"])
> 
> >          except getopt.error, msg:
> 
> >               raise Usage(msg)
> 
> >          # more code, unchanged
> 
> >      except Usage, err:
> 
> >          print >>sys.stderr, err.msg
> 
> >          print >>sys.stderr, "for help use --help"
> 
> >          return 2
> 
> >
> 
> > if __name__ == "__main__":
> 
> >      sys.exit(main())
> 
> >
> 
> >
> 
> >
> 
> >
> 
> > http://www.artima.com/weblogs/viewpost.jsp?thread=4829
> 
> >
> 
> >
> 
> Note how it explicitly prints err.msg.

Not in the raise statement. 

Adding the def __str__ made it work for me.
Thanks