On Jan 15, 2:03 pm, "Lambert, David W (S&T)" <lamber...@corning.com> wrote: > Overly terse. I do mean that this is illegal: > > isinstance(s, {str, bytes}) > > tuples have order, immutability, and the possibility of repeat items.
In the anticipated/usual use case (the type/class names are hard- coded): * order is a very mild plus (you can list them in descending order of (imagined) probability) * immutability is not a problem * the number of items is not likely to be so large that duplicate entries would creep in > A set is most reasonable in a mathematical sense. This is true -- distinguishing carefully between "most reasonable" and "the most reasonable" :-) Do you actually have a use case for dynamically assembling a collection of classes/types for use with isinstance(), or are you propelled solely by mathematical reasonableness? Cheers, John -- http://mail.python.org/mailman/listinfo/python-list