Guido van Rossum wrote:

>

> Do we want to support d[**kwargs]? It can be done, alternatively we could

> just ask the user to write the __getitem__/__setitem__ call explicitly.

> I think we should say no to d[*args], because that will just become

> d[(args)], with awkward questions around what if args == (1,). Maybe then

> for consistency we needn't bother with **kwargs, though the case for that

> is definitely stronger.

> Sorry for telegraphing this -- I am way past my bedtime but looking at this

> from the C API POV definitely made some things clear to me. I'm probably

> posting this in the wrong thread -- I can't keep up (and GMail splits

> threads after 100 messages, which doesn't help).



I hope I understood correctly because Mailman eats the * signs for formatting, but is it possible (and desirable) to have a different behaviour for *args and index when there is only one positional value ? Using "index" would keep the current behaviour : pass a tuple except when there is only one value, in that case the value is passes as-is. On the other hand if *args is passed in the signature, it always gets the positional arguments in a tuple, whatever their number. It would avoid the classical isinstance(index, tuple) check. Here are some examples of what I mean:



# Usual signature

class Simple:

    def __getitem__(self, index):

        print(index)

simple = Simple()

simple[0]  # 0

simple[0, 1]  # (0, 1)



# This is valid python, but useless ?

class Star:

    def __getitem__(self, *index):

        print(index)

star = Star()

star[0]  # (0,)

star[0, 1]  # ((0, 1),)



# I propose this breaking change

class NewStar:

    def __getitem__(self, *index):

        print(index)

star = Star()

star[0]  # (0,)

star[0, 1]  # (0, 1)



This is theoretically a breaking change, but who in his right mind would write such a Star class with the current python ?



Any thoughts ?

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