Depreate support for EOL PyQt4 and PySide

Tests/test_imageqt.py

@@ -2,6 +2,12 @@ from .helper import PillowTestCase, hopper
 
 from PIL import ImageQt
 
+try:
+    # Python 3
+    from importlib import reload
+except ImportError:
+    # Python 2.7
+    pass
 
 if ImageQt.qt_is_installed:
     from PIL.ImageQt import qRgba
@@ -78,3 +84,7 @@ class TestImageQt(PillowQtTestCase, PillowTestCase):
     def test_image(self):
         for mode in ('1', 'RGB', 'RGBA', 'L', 'P'):
             ImageQt.ImageQt(hopper(mode))
+
+    def test_deprecated(self):
+        expected = DeprecationWarning if ImageQt.qt_version in ["4", "side"] else None
+        self.assert_warning(expected, reload, ImageQt)

src/PIL/ImageQt.py

@@ -20,6 +20,7 @@ from . import Image
 from ._util import isPath, py3
 from io import BytesIO
 import sys
+import warnings
 
 qt_versions = [
     ['5', 'PyQt5'],
@@ -27,6 +28,12 @@ qt_versions = [
     ['4', 'PyQt4'],
     ['side', 'PySide']
 ]
+
+WARNING_TEXT = (
+    "Support for EOL {} is deprecated and will be removed in a future version. "
+    "Please upgrade to PyQt5 or PySide2."
+)
+
 # If a version has already been imported, attempt it first
 qt_versions.sort(key=lambda qt_version: qt_version[1] in sys.modules,
                  reverse=True)
@@ -41,9 +48,13 @@ for qt_version, qt_module in qt_versions:
         elif qt_module == 'PyQt4':
             from PyQt4.QtGui import QImage, qRgba, QPixmap
             from PyQt4.QtCore import QBuffer, QIODevice
+
+            warnings.warn(WARNING_TEXT.format(qt_module), DeprecationWarning)
         elif qt_module == 'PySide':
             from PySide.QtGui import QImage, qRgba, QPixmap
             from PySide.QtCore import QBuffer, QIODevice
+
+            warnings.warn(WARNING_TEXT.format(qt_module), DeprecationWarning)
     except (ImportError, RuntimeError):
         continue
     qt_is_installed = True
@@ -67,7 +78,7 @@ def fromqimage(im):
     """
     buffer = QBuffer()
     buffer.open(QIODevice.ReadWrite)
-    # preserve alha channel with png
+    # preserve alpha channel with png
     # otherwise ppm is more friendly with Image.open
     if im.hasAlphaChannel():
         im.save(buffer, 'png')