Fix indexing for scalar numpy values (#967) (#974)

* Fix indexing for scalar numpy values (#967)

* Fix linting errors

* Remove whitespace from GH editor

* Fix `W391 blank line at end of file`

Co-authored-by: Josh Moore <j.a.moore@dundee.ac.uk>
Co-authored-by: jmoore <josh@glencoesoftware.com>

Author: benjeffery

docs/release.rst

@@ -6,10 +6,17 @@ Release notes
 Unreleased
 ----------
 
+.. _release_2.11.1:
+
+2.11.1
+------
 
 Bug fixes
 ~~~~~~~~~
 
+* Fix bug where indexing with a scalar numpy value returned a single-value array.
+  By :user:`Ben Jeffery <benjeffery>` :issue:`967`.
+
 * Removed `clobber` argument from `normalize_store_arg`. This enables to change
   data within a opened consolidated group using mode `"r+"` (i.e region write).
   By :user:`Tobias Kölling <d70-t>` :issue:`975`.

zarr/indexing.py

@@ -34,7 +34,10 @@ def is_integer_list(x):
 
 
 def is_integer_array(x, ndim=None):
-    t = hasattr(x, 'shape') and hasattr(x, 'dtype') and x.dtype.kind in 'ui'
+    t = not np.isscalar(x) and \
+        hasattr(x, 'shape') and \
+        hasattr(x, 'dtype') and \
+        x.dtype.kind in 'ui'
     if ndim is not None:
         t = t and len(x.shape) == ndim
     return t

zarr/tests/test_indexing.py

@@ -1,3 +1,4 @@
+import numpy
 import numpy as np
 import pytest
 from numpy.testing import assert_array_equal
@@ -1442,3 +1443,11 @@ def test_slice_selection_uints():
     idx = np.uint64(3)
     slice_sel = make_slice_selection((idx,))
     assert arr[slice_sel].shape == (1, 6)
+
+
+def test_numpy_int_indexing():
+    a = np.arange(1050)
+    z = zarr.create(shape=1050, chunks=100, dtype=a.dtype)
+    z[:] = a
+    assert a[42] == z[42]
+    assert a[numpy.int64(42)] == z[numpy.int64(42)]