Help with Python Grammar change

[Timothy Docker]

Travis Oliphant <olipt at mayo.edu> writes:

> If a is a 3-dimensional array currently
> 
> a[:,:,5] returns a reference to a two-dimensional sub-array.
> 
> It would be useful if a(:,:,5) returned a copy to that array.  Using the
> current grammar we could make a(slice(None),slice(None),5) return the
> copy, but it is definitely not as clever.

You could have a subobject in a with a __getindex__ method, that does
the copy, as opposed to the __getindex__ method in a, that returns the
reference, ie


	a[:,:,5] returns a reference to a two-dimensional sub-array.

	a.copy[:,:,5] returns a copy of that array.

Tim