keras can not load imdb dataset

[Tony_Duan]

Hi ,

keras can not load imdb dataset.

library(keras)
imdb <- dataset_imdb(num_words = 10000)

------------ error message -------------------

Error in py_call_impl(callable, dots$args, dots$keywords): ValueError: Object arrays cannot be loaded when allow_pickle=False

Detailed traceback: 
  File "/usr/local/share/.virtualenvs/r-tensorflow/lib/python2.7/site-packages/tensorflow/python/keras/datasets/imdb.py", line 86, in load_data
    x_train, labels_train = f['x_train'], f['y_train']
  File "/usr/local/share/.virtualenvs/r-tensorflow/lib/python2.7/site-packages/numpy/lib/npyio.py", line 262, in __getitem__
    pickle_kwargs=self.pickle_kwargs)
  File "/usr/local/share/.virtualenvs/r-tensorflow/lib/python2.7/site-packages/numpy/lib/format.py", line 696, in read_array
    raise ValueError("Object arrays cannot be loaded when "

Traceback:

1. dataset_imdb()
2. keras$datasets$imdb$load_data(path = path, num_words = as_nullable_integer(num_words), 
 .     skip_top = as.integer(skip_top), maxlen = as_nullable_integer(maxlen), 
 .     seed = as.integer(seed), start_char = as.integer(start_char), 
 .     oov_char = as.integer(oov_char), index_from = as.integer(index_from))
3. py_call_impl(callable, dots$args, dots$keywords)