[Python-3000] PEP 3132: Extended Iterable Unpacking

Daniel Stutzbach daniel at stutzbachenterprises.com
Sat May 5 03:44:03 CEST 2007


On 5/4/07, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
> I don't think that returning the type given is a goal
> that should be attempted, because it can only ever work
> for a fixed set of known types. Given an arbitrary
> sequence type, there is no way of knowing how to
> create a new instance of it with specified contents.

For objects that support the sequence protocol, how about specifying that:

a, *b = container_object

must be equivalent to:

a, b = container_object[0], container_object[1:]

That way, b is assigned whatever container_object's getslice method
returns.  A list will return a list, a tuple will return a tuple, and
widgets (or BLists...) can return whatever makes sense for them.

-- 
Daniel Stutzbach, Ph.D.             President, Stutzbach Enterprises LLC


More information about the Python-3000 mailing list