Add repr for Color3DLUT

Tests/test_color_lut.py

@@ -1,5 +1,7 @@
 from __future__ import division
 
+from array import array
+
 from PIL import Image, ImageFilter
 from helper import unittest, PillowTestCase
 
@@ -264,8 +266,18 @@ class TestColorLut3DFilter(PillowTestCase):
         self.assertEqual(lut.table, list(range(24)))
 
         lut = ImageFilter.Color3DLUT((2, 2, 2), [(0, 1, 2, 3)] * 8,
-            channels=4)
+                                     channels=4)
 
+    def test_repr(self):
+        lut = ImageFilter.Color3DLUT(2, [0, 1, 2] * 8)
+        self.assertEqual(repr(lut),
+                         "<Color3DLUT from list size=2x2x2 channels=3>")
+
+        lut = ImageFilter.Color3DLUT(
+            (3, 4, 5), array('f', [0, 0, 0, 0] * (3 * 4 * 5)),
+            channels=4, target_mode='YCbCr', _copy_table=False)
+        self.assertEqual(repr(lut),
+            "<Color3DLUT from array size=3x4x5 channels=4 target_mode=YCbCr>")
 
 class TestGenerateColorLut3D(PillowTestCase):
     def test_wrong_channels_count(self):

src/PIL/ImageFilter.py

@@ -442,6 +442,15 @@ class Color3DLUT(MultibandFilter):
                           target_mode=target_mode or self.mode,
                           _copy_table=False)
 
+    def __repr__(self):
+        r = ["{0} from {1}".format(self.__class__.__name__,
+                                   self.table.__class__.__name__)]
+        r.append("size={0}x{1}x{2}".format(*self.size))
+        r.append("channels={0}".format(self.channels))
+        if self.mode:
+            r.append("target_mode={0}".format(self.mode))
+        return "<{}>".format(" ".join(r))
+
     def filter(self, image):
         from . import Image