added nan case

skimage/measure/_regionprops.py

@@ -329,9 +329,20 @@ class _RegionProperties(MutableMapping):
             return getattr(self, PROPS[key])
 
     def __eq__(self, other):
+        if not isinstance(other,_RegionProperties):
+            return False
+
         attr1 = np.array([getattr(self, k, None)for k in PROP_VALS])
         attr2 = np.array([getattr(other, k, None)for k in PROP_VALS])
-        return np.all(attr1 == attr2)
+
+        for x,y in zip(attr1, attr2):
+            try:
+                #so that NaNs are equal
+                np.testing.assert_equal(x,y)
+            except AssertionError :
+                return False
+
+        return True
 
 
 def regionprops(label_image, properties=None,