invalid data type 'str' at _convert_outputs in arrow_dataset.py
> Hi, actually the thing is I am getting the same error and even after tokenizing them I am passing them through batch_encode_plus.
> I dont know what seems to be the problem is. I even converted it into 'pt' while passing them through batch_encode_plus but when I am evaluating my model , i am getting this error
> 
> TypeError Traceback (most recent call last)
> in ()
> ----> 1 val_loss, predictions, true_val = evaluate(dataloader_validation)
> 2 val_f1 = f1_score_func(predictions, true_val)
> 3 tqdm.write(f'Validation loss: {val_loss}')
> 4 tqdm.write(f'F1 Score (Weighted): {val_f1}')
> 
> 6 frames
> /usr/local/lib/python3.6/dist-packages/torch/utils/data/dataset.py in (.0)
> 160
> 161 def **getitem**(self, index):
> --> 162 return tuple(tensor[index] for tensor in self.tensors)
> 163
> 164 def **len**(self):
> 
> TypeError: new(): invalid data type 'str'

I got the same error and fix it .
you can check your input where there may be string contained.
such as
```
a = [1,2,3,4,'<unk>']
torch.tensor(a)
```
I trying to build multi label text classifier model using Transformers lib. 

I'm using Transformers NLP to load the data set, while calling trainer.train() method. It throws the following error 

File "C:\***\arrow_dataset.py", line 343, in _convert_outputs
    v = command(v)
TypeError: new(): invalid data type 'str'

I'm using pyarrow 1.0.0.  And I have simple custom data set with Text and Integer Label.  
Ex: Data
 Text ,     Label  #Column Header
 I'm facing an Network issue, 1
 I forgot my password, 2

Error StackTrace:

File "C:\**\transformers\trainer.py", line 492, in train
    for step, inputs in enumerate(epoch_iterator):
  File "C:\**\tqdm\std.py", line 1104, in __iter__
    for obj in iterable:
  File "C:\**\torch\utils\data\dataloader.py", line 345, in __next__
    data = self._next_data()
  File "C:\**\torch\utils\data\dataloader.py", line 385, in _next_data
    data = self._dataset_fetcher.fetch(index)  # may raise StopIteration
  File "C:\**\torch\utils\data\_utils\fetch.py", line 44, in fetch
    data = [self.dataset[idx] for idx in possibly_batched_index]
  File "C:\**\torch\utils\data\_utils\fetch.py", line 44, in <listcomp>
    data = [self.dataset[idx] for idx in possibly_batched_index]
  File "C:\**\nlp\arrow_dataset.py", line 414, in __getitem__
    output_all_columns=self._output_all_columns,
  File "C:\**\nlp\arrow_dataset.py", line 403, in _getitem
    outputs, format_type=format_type, format_columns=format_columns, output_all_columns=output_all_columns
  File "C:\**\nlp\arrow_dataset.py", line 343, in _convert_outputs
    v = command(v)
TypeError: new(): invalid data type 'str'
 

invalid data type 'str' at _convert_outputs in arrow_dataset.py 
 I trying to build multi label text classifier model using Transformers lib. 

I'm using Transformers NLP to load the data set, while calling trainer.train() method. It throws the following error 

File "C:\***\arrow_dataset.py", line 343, in _convert_outputs
    v = command(v)
TypeError: new(): invalid data type 'str'

I'm using pyarrow 1.0.0.  And I have simple custom data set with Text and Integer Label.  
Ex: Data
 Text ,     Label  #Column Header
 I'm facing an Network issue, 1
 I forgot my password, 2

Error StackTrace:

File "C:\**\transformers\trainer.py", line 492, in train
    for step, inputs in enumerate(epoch_iterator):
  File "C:\**\tqdm\std.py", line 1104, in __iter__
    for obj in iterable:
  File "C:\**\torch\utils\data\dataloader.py", line 345, in __next__
    data = self._next_data()
  File "C:\**\torch\utils\data\dataloader.py", line 385, in _next_data
    data = self._dataset_fetcher.fetch(index)  # may raise StopIteration
  File "C:\**\torch\utils\data\_utils\fetch.py", line 44, in fetch
    data = [self.dataset[idx] for idx in possibly_batched_index]
  File "C:\**\torch\utils\data\_utils\fetch.py", line 44, in <listcomp>
    data = [self.dataset[idx] for idx in possibly_batched_index]
  File "C:\**\nlp\arrow_dataset.py", line 414, in __getitem__
    output_all_columns=self._output_all_columns,
  File "C:\**\nlp\arrow_dataset.py", line 403, in _getitem
    outputs, format_type=format_type, format_columns=format_columns, output_all_columns=output_all_columns
  File "C:\**\nlp\arrow_dataset.py", line 343, in _convert_outputs
    v = command(v)
TypeError: new(): invalid data type 'str'
 
 
 > Hi, actually the thing is I am getting the same error and even after tokenizing them I am passing them through batch_encode_plus.
> I dont know what seems to be the problem is. I even converted it into 'pt' while passing them through batch_encode_plus but when I am evaluating my model , i am getting this error
> 
> TypeError Traceback (most recent call last)
> in ()
> ----> 1 val_loss, predictions, true_val = evaluate(dataloader_validation)
> 2 val_f1 = f1_score_func(predictions, true_val)
> 3 tqdm.write(f'Validation loss: {val_loss}')
> 4 tqdm.write(f'F1 Score (Weighted): {val_f1}')
> 
> 6 frames
> /usr/local/lib/python3.6/dist-packages/torch/utils/data/dataset.py in (.0)
> 160
> 161 def **getitem**(self, index):
> --> 162 return tuple(tensor[index] for tensor in self.tensors)
> 163
> 164 def **len**(self):
> 
> TypeError: new(): invalid data type 'str'

I got the same error and fix it .
you can check your input where there may be string contained.
such as
```
a = [1,2,3,4,'<unk>']
torch.tensor(a)
```