Fix unit test failure

python/mxnet/ndarray/ndarray.py

@@ -442,6 +442,10 @@ def __setitem__(self, key, value):
         array([[ 6.,  5.,  5.],
                [ 6.,  0.,  4.]], dtype=float32)
         """
+        if self.ndim == 0 and key == ():
+            _internal._full(shape=self.shape, value=float(value), ctx=self.context,
+                            dtype=self.dtype, out=self)
+            return
         key = _indexing_key_expand_implicit_axes(key, self.shape)
         slc_key = tuple(idx for idx in key if idx is not None)
 
@@ -602,6 +606,8 @@ def __getitem__(self, key):
         array([[[4., 5.],
                 [6., 7.]]], dtype=float32)
         """
+        if self.ndim == 0 and key == ():
+            return self
         key = _indexing_key_expand_implicit_axes(key, self.shape)
         if len(key) == 0:
             raise ValueError('indexing key cannot be an empty tuple')
@@ -2741,6 +2747,8 @@ def _get_dim_size(start, stop, step):
     """Given start, stop, and stop, calculate the number of elements
     of this slice."""
     assert step != 0
+    if stop == start:
+        return 0
     if step > 0:
         assert start < stop
         dim_size = (stop - start - 1) // step + 1

python/mxnet/test_utils.py

@@ -1062,7 +1062,11 @@ def check_symbolic_forward(sym, location, expected, rtol=1E-4, atol=None,
 
     executor = sym.bind(ctx=ctx, args=location, args_grad=args_grad_data, aux_states=aux_states)
     for g in executor.grad_arrays:
-        g[:] = 0
+        print(g.shape)
+        if g.ndim == 0:
+            g[()] = 0
+        else:
+            g[:] = 0
 
     executor.forward(is_train=False)
 

tests/python/unittest/test_operator.py

@@ -8862,7 +8862,7 @@ def test_index_array_default():
 
     @mx.use_np_shape
     def test_index_array_default_zero_dim():
-        data  = mx.symbol.Variable("data")
+        data = mx.symbol.Variable("data")
         index_array = mx.sym.contrib.index_array(data)
 
         input_array = np.ones(())