`PyEllipsis` type

[samuelcolvin]

Would be great to have an Ellipsis type, aka ... in python.

The ffi type seems to exist

pyo3/pyo3-ffi/src/sliceobject.rs

Lines 11 to 13 in 18081ba

	pub unsafe fn Py_Ellipsis() -> *mut PyObject {
	addr_of_mut_shim!(_Py_EllipsisObject)
	}

But I'm not sure how I would use it in safe rust code.

[mejrs]

We can make a method for that just like None and NotImplemented : https://docs.rs/pyo3/latest/pyo3/marker/struct.Python.html#method.None

If you want it in safe rust right now, I think you'd need to get the builtins module, and then getattr the ellipsis object.

[samuelcolvin]

Thanks that would be great, that's what I was using, but your comment lead me to what I really needed which was simply

fn is_ellipsis(v: &PyAny) -> bool {
    unsafe { v.as_ptr() == Py_Ellipsis() }
}

Might be worth adding is_ellipsis as well like is_none?