Safely raise errors when object contains unicode

This safely turns nd.array objects that contain unicode into a
representation that can be printed

Author: janrito

pandas/util/testing.py

@@ -989,11 +989,11 @@ def assert_categorical_equal(left, right, check_dtype=True,
 
 def raise_assert_detail(obj, message, left, right, diff=None):
     if isinstance(left, np.ndarray):
-        left = pprint_thing(left)
+        left = repr(pprint_thing(left))
     elif is_categorical_dtype(left):
         left = repr(left)
     if isinstance(right, np.ndarray):
-        right = pprint_thing(right)
+        right = repr(pprint_thing(right))
     elif is_categorical_dtype(right):
         right = repr(right)