BUG/MAINT: Disallow non-native byteorder in random ints

Warn that non-native byte order is not supported in randint and integers

closes #13159

2 files changed, 13 insertions, 0 deletions

diff --git a/numpy/random/tests/test_generator_mt19937.py b/numpy/random/tests/test_generator_mt19937.py
index 192dcce08..64d87cd71 100644
--- a/numpy/random/tests/test_generator_mt19937.py
+++ b/numpy/random/tests/test_generator_mt19937.py
@@ -467,6 +467,10 @@ class TestIntegers(object):
             assert_equal(random.integers(0, -10, size=0).shape, (0,))
             assert_equal(random.integers(10, 10, size=0).shape, (0,))
 
+    def test_error_byteorder(self):
+        other_byteord_dt = '<i4' if sys.byteorder == 'big' else '>i4'
+        with pytest.raises(ValueError):
+            random.integers(0, 200, size=10, dtype=other_byteord_dt)
 
 class TestRandomDist(object):
     # Make sure the random distribution returns the correct value for a
diff --git a/numpy/random/tests/test_randomstate_regression.py b/numpy/random/tests/test_randomstate_regression.py
index 9c319319e..5bb1ddde5 100644
--- a/numpy/random/tests/test_randomstate_regression.py
+++ b/numpy/random/tests/test_randomstate_regression.py
@@ -1,4 +1,7 @@
 import sys
+
+import pytest
+
 from numpy.testing import (
     assert_, assert_array_equal, assert_raises,
     )
@@ -155,3 +158,9 @@ class TestRegression(object):
         perm = random.permutation(m)
         assert_array_equal(perm, np.array([2, 1, 4, 0, 3]))
         assert_array_equal(m.__array__(), np.arange(5))
+
+    def test_warns_byteorder(self):
+        # GH 13159
+        other_byteord_dt = '<i4' if sys.byteorder == 'big' else '>i4'
+        with pytest.deprecated_call(match='non-native byteorder is not'):
+            random.randint(0, 200, size=10, dtype=other_byteord_dt)