scikit-learn · glemaitre · Feb 26, 2019 · Feb 25, 2019 · Feb 25, 2019 · Feb 25, 2019
diff --git a/doc/whats_new/v0.21.rst b/doc/whats_new/v0.21.rst
@@ -66,6 +66,9 @@ Support for Python 3.4 and below has been officially dropped.
   :class:`datasets.svmlight_format` :issue:`10727` by
   :user:`Bryan K Woods <bryan-woods>`.
 
+- |Fix| :func:`datasets.load_sample_images` returns images with a deterministic
+  order. :issue:`13250` by :user:`Thomas Fan <thomasjpfan>`.
+
 :mod:`sklearn.decomposition`
 ............................
 

diff --git a/sklearn/datasets/base.py b/sklearn/datasets/base.py
@@ -794,7 +794,7 @@ def load_sample_images():
     with open(join(module_path, 'README.txt')) as f:
         descr = f.read()
     filenames = [join(module_path, filename)
-                 for filename in os.listdir(module_path)
+                 for filename in sorted(os.listdir(module_path))
                  if filename.endswith(".jpg")]
     # Load image data for each image in the source folder.
     images = [imread(filename) for filename in filenames]

diff --git a/sklearn/datasets/tests/test_base.py b/sklearn/datasets/tests/test_base.py
@@ -9,6 +9,7 @@
 
 import pytest
 
+import numpy as np
 from sklearn.datasets import get_data_home
 from sklearn.datasets import clear_data_home
 from sklearn.datasets import load_files
@@ -123,6 +124,14 @@ def test_load_sample_images():
         res = load_sample_images()
         assert_equal(len(res.images), 2)
         assert_equal(len(res.filenames), 2)
+        images = res.images
+
+        # assert is china image
+        assert np.all(images[0][0, 0, :] ==
+                      np.array([174, 201, 231], dtype=np.uint8))
+        # assert is flower image
+        assert np.all(images[1][0, 0, :] ==
+                      np.array([2, 19, 13], dtype=np.uint8))
         assert res.DESCR
     except ImportError:
         warnings.warn("Could not load sample images, PIL is not available.")