Python Bindings didn't allow for zero-D Funcs, ImageParams, Buffers

[steven-johnson]

There were no overloads or tests for accessing the element of any of these in the zero-D case, and the obvious syntax ([], to mirror C++ () in these cases) isn't legal in Python. To support this uncommon-but-necessary case, I'm proposing that we use the syntax [None], [()], which isn't pretty, but is less bad than other options I've considered so far. (Suggestions welcome.)

[abadams]

An alternative to None might be the empty tuple: [()]

[alexreinking]

None is fine. It's the most obvious thing besides the obvious, but illegal, syntax.

[steven-johnson]

FWIW, [()] works even without this PR (we'd want to add the test cases, of course). I can live with either syntax.

[steven-johnson]

Final votes on syntax?

[alexreinking]

Final votes on syntax?

On second thought, we shouldn't use None for this... Numpy uses it in its indexing logic to introduce a new axis of extent 1. That's not what's happening here, so to allow None in this case might well cause confusion. Let's go with the empty tuple and just make sure it's tested.

https://numpy.org/doc/stable/reference/constants.html#numpy.newaxis

[steven-johnson]

PTAL