FIX: provide __ne__ implementation for transforms in py2

tacaswell · tacaswell · commit b5bc6aa85f46 · 2017-10-17T23:55:15.000-04:00
Closes #9455 The issue is that due to `!=` not defaulting to `not a == b` in python2 (unlike python3) an internal check was failing and the y ticks (aka the radial ticks) were being regenerated on every draw and the alpha settings did not properly propagate. This fix is a band-aid to make the behavior the same on all versions of python.
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -5353,3 +5353,19 @@ def test_patch_deprecations():
         assert fig.patch == fig.figurePatch
 
     assert len(w) == 2
+
+
+def test_polar_gridlines():
+    fig = plt.figure()
+    ax = fig.add_subplot(111, polar=True)
+
+    # make all major grid lines lighter, only x grid lines set in 2.1.0
+    ax.grid(alpha=0.2)
+
+    # hide y tick labels, no effect in 2.1.0
+    plt.setp(ax.yaxis.get_ticklabels(), visible=False)
+
+    fig.canvas.draw()
+
+    assert ax.xaxis.majorTicks[0].gridline.get_alpha() == .2
+    assert ax.yaxis.majorTicks[0].gridline.get_alpha() == .2
diff --git a/lib/matplotlib/transforms.py b/lib/matplotlib/transforms.py
@@ -1287,6 +1287,10 @@ def __radd__(self, other):
     # override `__eq__`), but some subclasses, such as TransformWrapper &
     # AffineBase, override this behavior.
 
+    if six.PY2:
+        def __ne__(self, other):
+            return not (self == other)
+
     def _iter_break_from_left_to_right(self):
         """
         Returns an iterator breaking down this transform stack from left to
