pandas: Error Indexing DafaFrame with a 0-d array

>>> df = pd.DataFrame([[1, 2], [3, 4]], columns=['a', 'b'])
>>> ar = np.array(0)
>>> df.iloc[ar]
Traceback (most recent call last):
  ...
  ...
  File "/home/float2/Documents/Python/Pandas/pandas/pandas/core/indexes/base.py", line 529, in _shallow_copy_with_infer
    if not len(values) and 'dtype' not in kwargs:
TypeError: object of type 'numpy.int64' has no len()

A 0-d array passes this check cause it is an Iterable. But later, when len() is called on, TypeError is raised. It would be nice to implement PEP 357 to prevent this error. The matter has been raised at PyTorch project. #9237