[GitHub] [incubator-mxnet] sxjscience commented on issue #18672: Gluon 2.0 Dataloader should support BERT training using GluonNLP

[GitBox <gi...@apache.org>]

sxjscience commented on issue #18672:
URL: https://github.com/apache/incubator-mxnet/issues/18672#issuecomment-655658852


   I can reproduce this failure message:
   
   ```python
   import mxnet as mx
   import numpy as np
   mx.npx.set_np()
   a = np.ndarray(shape=(128,)) # similar to one feature of one sequence
   b = np.ndarray(shape=(19,))
   l1 = [a,b] # similar to one feature of all sequences
   l2 = [a,b]
   c = [l1, l2] # similar to a training instance that will be sampled against
   ds = mx.gluon.data.ArrayDataset(*c)
   dt = mx.gluon.data.DataLoader(dataset=ds, batch_size=1, num_workers=1, try_nopython=True)
   print('ok') # error out before prints
   ```
   
   Error message:
   
   ```python
   ~/miniconda3/lib/python3.7/site-packages/mxnet/gluon/data/dataset.py in __mx_handle__(self)
       383                     datasets.append(data.__mx_handle__())
       384                 else:
   --> 385                     datasets.append(NDArrayDataset(arr=default_array(data)))
       386             self.handle = GroupDataset(datasets=datasets)
       387         return self.handle
   
   ~/miniconda3/lib/python3.7/site-packages/mxnet/util.py in default_array(source_array, ctx, dtype)
       936     from . import np as _mx_np
       937     if is_np_array():
   --> 938         return _mx_np.array(source_array, ctx=ctx, dtype=dtype)
       939     else:
       940         return _mx_nd.array(source_array, ctx=ctx, dtype=dtype)
   
   ~/miniconda3/lib/python3.7/site-packages/mxnet/numpy/multiarray.py in array(object, dtype, ctx)
      2407             # printing out the error raised by official NumPy's array function
      2408             # for transparency on users' side
   -> 2409             raise TypeError('{}'.format(str(e)))
      2410     ret = empty(object.shape, dtype=dtype, ctx=ctx)
      2411     if len(object.shape) == 0:
   
   TypeError: setting an array element with a sequence.
   ```


----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

For queries about this service, please contact Infrastructure at:
users@infra.apache.org