address comments

python/mxnet/numpy/multiarray.py

@@ -1995,15 +1995,15 @@ def array(object, dtype=None, ctx=None):
         ctx = current_context()
     if isinstance(object, (ndarray, _np.ndarray)):
         dtype = object.dtype if dtype is None else dtype
+    elif isinstance(object, NDArray):
+        raise ValueError("")
     else:
-        dtype = _np.float32 if dtype is None else dtype
-        if hasattr(object, "dtype"):
-            dtype = object.dtype
-        if not isinstance(object, (ndarray, _np.ndarray)):
-            try:
-                object = _np.array(object, dtype=dtype)
-            except Exception as e:
-                raise TypeError('{}'.format(str(e)))
+        if dtype is None:
+            dtype = object.dtype if hasattr(object, "dtype") else _np.float32
+        try:
+            object = _np.array(object, dtype=dtype)
+        except Exception as e:
+            raise TypeError('{}'.format(str(e)))
     ret = empty(object.shape, dtype=dtype, ctx=ctx)
     if len(object.shape) == 0:
         ret[()] = object

tests/python/unittest/test_numpy_ndarray.py

@@ -96,13 +96,12 @@ def test_np_array_creation():
         for src in objects:
             mx_arr = np.array(src, dtype=dtype)
             assert mx_arr.ctx == mx.current_context()
-            np_dtype = _np.float32 if dtype is None else dtype
-            if dtype is None and isinstance(src, _np.ndarray):
-                np_dtype = src.dtype
+            if dtype is None:
+                dtype = src.dtype if isinstance(src, _np.ndarray) else _np.float32
             if isinstance(src, mx.nd.NDArray):
-                np_arr = _np.array(src.asnumpy(), dtype=np_dtype)
+                np_arr = _np.array(src.asnumpy(), dtype=dtype)
             else:
-                np_arr = _np.array(src, dtype=np_dtype)
+                np_arr = _np.array(src, dtype=dtype)
             assert mx_arr.dtype == np_arr.dtype
             assert same(mx_arr.asnumpy(), np_arr)