Thank you Steven and Konstantin, that clears things up. Sometimes I forget how incomplete my Python Essential Reference is.
James On Monday 20 June 2005 05:40 pm, Steven Bethard wrote: > Well, it's not a bug, because that's what the documentation says it'll do: > > "The second object is used to determine the exception value: If it is an > instance of the class, the instance becomes the exception value. If the > second object is a tuple, it is used as the argument list for the class > constructor; if it is None, an empty argument list is used, and any > other object is treated as a single argument to the constructor."[1] > > In the example above (as well as almost all code), there's no need to > use the two argument version of raise. You can simply write: > > raise MyErr(sometup) > > If you need the three argument version of raise, I believe you can still > write it as: > > raise MyErr(sometup), None, tb > > Note that Guido has mentioned a few times that in Python 3.0, he wants > tracebacks to be attributes of the Exception objects so that all raise > statements are like the one argument version. > > STeVe > > P.S. If you insist on using the two argument version of raise, you can > do it like this: > > py> class E(Exception): > ... def __init__(self, atup): > ... Exception.__init__(self, "Error with %s-%s" % atup) > ... > py> raise E, ((1, 2),) > Traceback (most recent call last): > File "<interactive input>", line 1, in ? > E: Error with 1-2 > > But that seems a lot less elegant than simply using the one argument > version. > > [1] http://docs.python.org/ref/raise.html -- James Stroud UCLA-DOE Institute for Genomics and Proteomics Box 951570 Los Angeles, CA 90095 http://www.jamesstroud.com/ -- http://mail.python.org/mailman/listinfo/python-list
