Merge pull request #8641 from eric-wieser/ix_-preserve-type

BUG: Preserve types of empty arrays in ix_ when known

1 files changed, 10 insertions, 5 deletions

diff --git a/numpy/lib/tests/test_index_tricks.py b/numpy/lib/tests/test_index_tricks.py
index 028bba37d..e687e2f54 100644
--- a/numpy/lib/tests/test_index_tricks.py
+++ b/numpy/lib/tests/test_index_tricks.py
@@ -292,11 +292,16 @@ class TestIndexExpression(object):
 
 class TestIx_(object):
     def test_regression_1(self):
-        # Test empty inputs create outputs of indexing type, gh-5804
-        # Test both lists and arrays
-        for func in (range, np.arange):
-            a, = np.ix_(func(0))
-            assert_equal(a.dtype, np.intp)
+        # Test empty untyped inputs create outputs of indexing type, gh-5804
+        a, = np.ix_(range(0))
+        assert_equal(a.dtype, np.intp)
+
+        a, = np.ix_([])
+        assert_equal(a.dtype, np.intp)
+
+        # but if the type is specified, don't change it
+        a, = np.ix_(np.array([], dtype=np.float32))
+        assert_equal(a.dtype, np.float32)
 
     def test_shape_and_dtype(self):
         sizes = (4, 5, 3, 2)