(This should probably be discussed on the Python Ideas mailing list...)

I definitely like the idea of being able to construct slices etc. using "[]" syntax. I think this should be considered even if it is decided not to change the repr() of slices.

An important note here is that this is about more than slices:

$ python3
Python 3.4.2 (default, Feb 23 2015, 21:16:28)
[GCC 4.2.1 Compatible Apple LLVM 5.1 (clang-503.0.40)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> class A:
...     def __getitem__(self, *args):
...         print(repr(args))
...
>>> a = A()
>>> a[0]
(0,)
>>> a[0:1]
(slice(0, 1, None),)
>>> a[0:1, ..., 1:2]
((slice(0, 1, None), Ellipsis, slice(1, 2, None)),)
>>> a[0:1, 2]
((slice(0, 1, None), 2),)

Indeed, Joe's suggested slice.literal supports all of this, but we can't just modify slice to handle all of these cases.

What I'm missing is a way to use such an object to actually index/slice something. The only way I can currently think of is using a.__getitem__(), but that's quite ugly IMO.