Add deprecated scipy image-related functions in externals._pilutil (s…

…cikit-learn#10427)

.travis.yml

@@ -36,14 +36,14 @@ matrix:
     # Python 3.4 build
     - env: DISTRIB="conda" PYTHON_VERSION="3.4" INSTALL_MKL="false"
            NUMPY_VERSION="1.10.4" SCIPY_VERSION="0.16.1" CYTHON_VERSION="0.25.2"
-           COVERAGE=true
+           PILLOW_VERSION="4.0.0" COVERAGE=true
       if: type != cron
     # This environment tests the newest supported Anaconda release (5.0.0)
     # It also runs tests requiring Pandas and PyAMG
     - env: DISTRIB="conda" PYTHON_VERSION="3.6.2" INSTALL_MKL="true"
            NUMPY_VERSION="1.13.1" SCIPY_VERSION="0.19.1" PANDAS_VERSION="0.20.3"
-           CYTHON_VERSION="0.26.1" PYAMG_VERSION="3.3.2" COVERAGE=true
-           CHECK_PYTEST_SOFT_DEPENDENCY="true"
+           CYTHON_VERSION="0.26.1" PYAMG_VERSION="3.3.2" PILLOW_VERSION="4.3.0"
+           COVERAGE=true CHECK_PYTEST_SOFT_DEPENDENCY="true"
       if: type != cron
     # flake8 linting on diff wrt common ancestor with upstream/master
     - env: RUN_FLAKE8="true" SKIP_TESTS="true"

build_tools/appveyor/requirements.txt

@@ -13,3 +13,4 @@ cython
 pytest
 wheel
 wheelhouse_uploader
+pillow

build_tools/travis/install.sh

@@ -55,6 +55,10 @@ if [[ "$DISTRIB" == "conda" ]]; then
         TO_INSTALL="$TO_INSTALL pyamg=$PYAMG_VERSION"
     fi
 
+    if [[ -n "$PILLOW_VERSION" ]]; then
+        TO_INSTALL="$TO_INSTALL pillow=$PILLOW_VERSION"
+    fi
+
     conda create -n testenv --yes $TO_INSTALL
     source activate testenv
 

sklearn/datasets/base.py

@@ -767,16 +767,9 @@ def load_sample_images():
     >>> first_img_data.dtype               #doctest: +SKIP
     dtype('uint8')
     """
-    # Try to import imread from scipy. We do this lazily here to prevent
-    # this module from depending on PIL.
-    try:
-        try:
-            from scipy.misc import imread
-        except ImportError:
-            from scipy.misc.pilutil import imread
-    except ImportError:
-        raise ImportError("The Python Imaging Library (PIL) "
-                          "is required to load data from jpeg files")
+    # import PIL only when needed
+    from ..externals._pilutil import imread
+
     module_path = join(dirname(__file__), "images")
     with open(join(module_path, 'README.txt')) as f:
         descr = f.read()

sklearn/datasets/lfw.py

@@ -32,7 +32,6 @@
 from .base import get_data_home, _fetch_remote, RemoteFileMetadata
 from ..utils import Bunch
 from ..externals.joblib import Memory
-
 from ..externals.six import b
 
 logger = logging.getLogger(__name__)
@@ -136,18 +135,8 @@ def check_fetch_lfw(data_home=None, funneled=True, download_if_missing=True):
 
 def _load_imgs(file_paths, slice_, color, resize):
     """Internally used to load images"""
-
-    # Try to import imread and imresize from PIL. We do this here to prevent
-    # the whole sklearn.datasets module from depending on PIL.
-    try:
-        try:
-            from scipy.misc import imread
-        except ImportError:
-            from scipy.misc.pilutil import imread
-        from scipy.misc import imresize
-    except ImportError:
-        raise ImportError("The Python Imaging Library (PIL)"
-                          " is required to load data from jpeg files")
+    # import PIL only when needed
+    from ..externals._pilutil import imread, imresize
 
     # compute the portion of the images to load to respect the slice_ parameter
     # given by the caller

sklearn/datasets/tests/test_base.py

@@ -21,6 +21,7 @@
 from sklearn.datasets.base import Bunch
 
 from sklearn.externals.six import b, u
+from sklearn.externals._pilutil import pillow_installed
 
 from sklearn.utils.testing import assert_false
 from sklearn.utils.testing import assert_true
@@ -161,15 +162,7 @@ def test_load_sample_image():
 
 
 def test_load_missing_sample_image_error():
-    have_PIL = True
-    try:
-        try:
-            from scipy.misc import imread
-        except ImportError:
-            from scipy.misc.pilutil import imread  # noqa
-    except ImportError:
-        have_PIL = False
-    if have_PIL:
+    if pillow_installed:
         assert_raises(AttributeError, load_sample_image,
                       'blop.jpg')
     else:

sklearn/datasets/tests/test_lfw.py

@@ -14,14 +14,7 @@
 import tempfile
 import numpy as np
 from sklearn.externals import six
-try:
-    try:
-        from scipy.misc import imsave
-    except ImportError:
-        from scipy.misc.pilutil import imsave
-except ImportError:
-    imsave = None
-
+from sklearn.externals._pilutil import pillow_installed, imsave
 from sklearn.datasets import fetch_lfw_pairs
 from sklearn.datasets import fetch_lfw_people
 
@@ -48,7 +41,7 @@
 
 def setup_module():
     """Test fixture run once and common to all tests of this module"""
-    if imsave is None:
+    if not pillow_installed:
         raise SkipTest("PIL not installed.")
 
     if not os.path.exists(LFW_HOME):