Merge pull request numpy#26384 from WarrenWeckesser/fix-gh-26375

BUG: Fix incorrect return type of item with length 0 from chararray.__getitem__

Author: ngoldbaum

numpy/_core/defchararray.py

@@ -577,14 +577,8 @@ def __array_finalize__(self, obj):
 
     def __getitem__(self, obj):
         val = ndarray.__getitem__(self, obj)
-
         if isinstance(val, character):
-            temp = val.rstrip()
-            if len(temp) == 0:
-                val = ''
-            else:
-                val = temp
-
+            return val.rstrip()
         return val
 
     # IMPLEMENTATION NOTE: Most of the methods of this class are

numpy/_core/tests/test_defchararray.py

@@ -738,6 +738,16 @@ def test_slice(self):
 
         assert_(arr[0, 0] == b'abc')
 
+    @pytest.mark.parametrize('data', [['plate', '   ', 'shrimp'],
+                                      [b'retro', b'  ', b'encabulator']])
+    def test_getitem_length_zero_item(self, data):
+        # Regression test for gh-26375.
+        a = np.char.array(data)
+        # a.dtype.type() will be an empty string or bytes instance.
+        # The equality test will fail if a[1] has the wrong type
+        # or does not have length 0.
+        assert_equal(a[1], a.dtype.type())
+
 
 class TestMethodsEmptyArray:
     def setup_method(self):