On Wed, Jun 20, 2012 at 12:36 PM, Yury Selivanov <[email protected]> wrote: > On 2012年06月19日, at 9:22 PM, Yury Selivanov wrote: >> On 2012年06月19日, at 8:39 PM, Nick Coghlan wrote: >>> 7. The idea of immutable Signature objects does highlight an annoyance >>> with the "attribute may be missing" style APIs. To actually duplicate >>> a signature correctly, including its return annotation (and assuming >>> the attribute is renamed), you would have to do something like: >>> >>> try: >>> note = {"annotation": old_sig.annotation} >>> except AttributeError: >>> note = {} >>> new_sig = Signature(old_sig.parameters[1:], **note) > > BTW, we don't have slices for OrderedDict. Since the slice object is > not hashable, we can implement it safely. I can create an issue (and draft > implementation), as I think it'd be quite a useful feature.
No need, my example was just wrong, it should be: new_sig = Signature(old_sig.parameters.values()[1:]) The constructor accepts an iterable of Parameter objects rather than a mapping. Cheers, Nick. -- Nick Coghlan | [email protected] | Brisbane, Australia _______________________________________________ Python-Dev mailing list [email protected] http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com