This undocumented method has puzzling behaviour.
[Dbg]>>> a
array([[0, 1, 2],
[3, 4, 5],
[6, 7, 8]])
[Dbg]>>> b= a[1:1]
[Dbg]>>> b
array([])
[Dbg]>>> b.shape
(0, 3)
[Dbg]>>> b.rank
2
I had expected a rank of zero and an indeterminate shape.
Colin W.