Indeed, the helper function I wrote for xray was not designed to handle None/np.newaxis or non-1d Boolean indexers, because those are not valid indexers for xray objects. I think it could be straightforwardly extended to handle None simply by not counting them towards the total number of dimensions. On Tue, Aug 25, 2015 at 8:41 AM, Fabien <fabien.maussion@gmail.com> wrote:
I think that Stephan's function for xray is very useful. A possible improvement (probably at a certain performance cost) would be to be able to provide a shape instead of a number of dimensions. The output would then be slices with valid start and ends.
Current behavior: In[9]: expanded_indexer(slice(None), 2) Out[9]: (slice(None, None, None), slice(None, None, None))
With shape: In[9]: expanded_indexer(slice(None), (3, 4)) Out[9]: (slice(0, 4, 1), slice(0, 5, 1))
But if nobody needed something like this before me, I think that I might have a design problem in my code (still quite new to python).
Glad you found it helpful! Python's slice object has the indices method which implements this logic, e.g., In [15]: s = slice(None, 10) In [16]: s.indices(100) Out[16]: (0, 10, 1) Cheers, Stephan