On Fri, Jun 22, 2012 at 12:24 PM, Yury Selivanov <yselivanov...@gmail.com> wrote: > On 2012-06-22, at 3:18 PM, Guido van Rossum wrote: > >> On Fri, Jun 22, 2012 at 12:10 PM, Yury Selivanov >> <yselivanov...@gmail.com> wrote: >>> Guido, >>> >>> On 2012-06-22, at 2:52 PM, Guido van Rossum wrote: > ... >>> 'empty' will also work. When python-dev collectively decided to >>> go with missing attributes, 'empty' didn't yet exist (we added >>> it with 'replace()' methods). >>> >>> If you think that using 'empty' is better, we can add that to the PEP. >> >> Yes, please do. > > OK > >>>> (2) Could use an example on how to remove and add parameters using >>>> replace(). >>> >>> You have to build a new list of parameters and then pass it to 'replace()'. >>> Example (from the actual signature() function implementation): >>> >>> if isinstance(obj, types.MethodType): >>> # In this case we skip the first parameter of the underlying >>> # function (usually `self` or `cls`). >>> sig = signature(obj.__func__) >>> return sig.replace(parameters=tuple(sig.parameters.values())[1:]) >>> >>>> (3) You are using name(arg1, *, arg2) a lot. I think in most cases you >>>> mean for arg2 to be an optional keyword arg, but this notation doesn't >>>> convey that it is optional. Can you clarify? >>> >>> Yes, I meant optional. Would 'name(arg1, *, [arg2])' be better? >> >> Hardly, because that's not valid syntax. I'd write name(arg1, *, >> arg2=<default>). > > Like > > replace(*, name=<default>, kind=<default>, default=<default>, > annotation=<default>) -> Parameter > > or > > replace(*, name=<optional>, kind=<optional>, default=<optional>, > annotation=<optional>) -> Parameter
Either one's an improvement, but you'll have to explain at the top of the PEP what you intend this notation to mean. I'd go with <optional> since the key thing here seems to be that various keywords, when not specified, mean that nothing changes. OTOH in some places you can probably write "foo=Signature.empty" (etc.). >>>> (4) "If the object is a method" -- shouldn't that be "bound method"? >>>> (Unbound methods are undetectable.) Or is there some wider definition >>>> of method? What does it do for static or class methods? >>> >>> Yes, it should be "If the object is a bound method". We'll fix this >>> shortly. >> >> Great. >> >>> classmethod as a descriptor returns a BoundMethod (bound to the class), >>> staticmethod returns the original unmodified function, so both of >>> them are supported automatically. >> >> Oh, great. IIRC it wasn't always like that. Maybe just add this to the >> PEP as a note? > > OK. I'll clarify that. > > - > Yury -- --Guido van Rossum (python.org/~guido) _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
