MAINT: Add comment to unused func, silence linter and avoid non-contig error

3 files changed, 18 insertions, 12 deletions

diff --git a/numpy/core/src/multiarray/lowlevel_strided_loops.c.src b/numpy/core/src/multiarray/lowlevel_strided_loops.c.src
index 8a6948fa4..631042dae 100644
--- a/numpy/core/src/multiarray/lowlevel_strided_loops.c.src
+++ b/numpy/core/src/multiarray/lowlevel_strided_loops.c.src
@@ -285,6 +285,11 @@ _strided_to_strided(
     return 0;
 }
 
+/*
+ * NOTE: This function is currently unused. It would currently be used for
+ *       builtin dtypes that have an elsize other than 2, 4, 8, or 16 bytes.
+ *       Since unicode and complex swap differently, no such dtype exists.
+ */
 static int
 _swap_strided_to_strided(
         PyArrayMethod_Context *context, char *const *args,
diff --git a/numpy/core/tests/test_casting_unittests.py b/numpy/core/tests/test_casting_unittests.py
index 45d58a23a..c8fcd4b42 100644
--- a/numpy/core/tests/test_casting_unittests.py
+++ b/numpy/core/tests/test_casting_unittests.py
@@ -626,20 +626,20 @@ class TestCasting:
         # that tests unicode bytedwaps including for unaligned array data.
         dtype1 = np.dtype(f"{order1}U30")
         dtype2 = np.dtype(f"{order2}U30")
-        data1 = np.empty(30 * 4 + 1, dtype=np.uint8)[None, 1:].view(dtype1)
-        data2 = np.empty(30 * 4 + 1, dtype=np.uint8)[None, 1:].view(dtype2)
+        data1 = np.empty(30 * 4 + 1, dtype=np.uint8)[1:].view(dtype1)
+        data2 = np.empty(30 * 4 + 1, dtype=np.uint8)[1:].view(dtype2)
         if dtype1.alignment != 1:
             # alignment should always be >1, but skip the check if not
             assert not data1.flags.aligned
             assert not data2.flags.aligned
 
         element = "this is a ünicode string‽"
-        data1[0] = element
+        data1[()] = element
         # Test both `data1` and `data1.copy()`  (which should be aligned)
         for data in [data1, data1.copy()]:
             data2[...] = data1
-            assert data2[0] == element
-            assert data2.copy()[0] == element
+            assert data2[()] == element
+            assert data2.copy()[()] == element
 
     def test_void_to_string_special_case(self):
         # Cover a small special case in void to string casting that could
diff --git a/numpy/core/tests/test_datetime.py b/numpy/core/tests/test_datetime.py
index d2c04a506..b4146eadf 100644
--- a/numpy/core/tests/test_datetime.py
+++ b/numpy/core/tests/test_datetime.py
@@ -705,12 +705,12 @@ class TestDateTime:
 
         # Test that every byte-swapping combination also returns the same
         # results (previous tests check that this comparison works fine).
-        res1 = times.astype(dtype1.newbyteorder()).astype(dtype2)
-        assert_array_equal(res1, expected)
-        res2 = times.astype(dtype2.newbyteorder())
-        assert_array_equal(res2, expected)
-        res3 = times.astype(dtype1.newbyteorder()).astype(dtype2.newbyteorder())
-        assert_array_equal(res3, expected)
+        res = times.astype(dtype1.newbyteorder()).astype(dtype2)
+        assert_array_equal(res, expected)
+        res = times.astype(dtype2.newbyteorder())
+        assert_array_equal(res, expected)
+        res = times.astype(dtype1.newbyteorder()).astype(dtype2.newbyteorder())
+        assert_array_equal(res, expected)
 
     @pytest.mark.parametrize("time_dtype", ["m8[D]", "M8[Y]"])
     @pytest.mark.parametrize("str_dtype", ["U", "S"])
@@ -732,7 +732,8 @@ class TestDateTime:
         assert_array_equal(res, to_strings)
 
         # Check that conversion from string to times works if src is swapped:
-        from_strings_swapped = from_strings.astype(from_strings.dtype.newbyteorder())
+        from_strings_swapped = from_strings.astype(
+                from_strings.dtype.newbyteorder())
         res = from_strings_swapped.astype(time_dtype)
         assert_array_equal(res, times)
         # And if both are swapped: