There appears to be an error in the code example on this page: http://www.twistedmatrix.com/documents/howto/options <quote> Inheritance, Or: How I Learned to Stop Worrying and Love the Superclass Sometimes there is a need for several option processors with a unifying core. Perhaps you want all your commands to understand -q/--quiet means to be quiet, or something similar. On the face of it, this looks impossible: in Python, the subclass's optFlags would shadow the superclass's. However, usage.Options uses special reflection code to get all of the optFlags defined in the hierarchy. So the following: class BaseOptions(usage.Options): optFlags = [["quiet", "q"], None] class SpecificOptions(BaseOptions): optFlags = [ ["fast", "f", None], ["good", "g", None], ["cheap", "c", None] ] Is the same as: class SpecificOptions(BaseOptions): optFlags = [ ["quiet", "q", "Silence output"], ["fast", "f", "Run quickly"], ["good", "g", "Don't validate input"], ["cheap", "c", "Use cheap resources"] ] </quote> I don't see how the descriptions in the second SpecificOptions class match with the use of None in the first set of classes. Twisted is good, but it isn't *that* good, is it? -- Patrick K. O'Brien Orbtech http://www.orbtech.com/web/pobrien ----------------------------------------------- "Your source for Python programming expertise." -----------------------------------------------