helmo/github-issues huggingface dataset:
OverflowError when slicing with an array containing negative ids
State: closed | Author: lhoestq (MEMBER)

```python
from datasets import Dataset

d = ds.Dataset.from_dict({"a": range(10)})

print(d[0])
# {'a': 0}

print(d[-1])
# {'a': 9}

print(d[[0, -1]])
# OverflowError
```
results in
```
---------------------------------------------------------------------------
OverflowError                             Traceback (most recent call last)
<ipython-input-5-863dc3555598> in <module>
----> 1 d[[0, -1]]

~/Desktop/hf/nlp/src/datasets/arrow_dataset.py in __getitem__(self, key)
   1070             format_columns=self._format_columns,
   1071             output_all_columns=self._output_all_columns,
-> 1072             format_kwargs=self._format_kwargs,
   1073         )
   1074 

~/Desktop/hf/nlp/src/datasets/arrow_dataset.py in _getitem(self, key, format_type, format_columns, output_all_columns, format_kwargs)
   1025                 indices = key
   1026 
-> 1027             indices_array = pa.array([int(i) for i in indices], type=pa.uint64())
   1028 
   1029             # Check if we need to convert indices

~/.virtualenvs/hf-datasets/lib/python3.7/site-packages/pyarrow/array.pxi in pyarrow.lib.array()

~/.virtualenvs/hf-datasets/lib/python3.7/site-packages/pyarrow/array.pxi in pyarrow.lib._sequence_to_array()

OverflowError: can't convert negative value to unsigned int
```
Loss not decrease with Datasets and Transformers
State: closed | Author: wangcongcong123 (NONE)

HI,

The following script is used to fine-tune a BertForSequenceClassification model on SST2.

The script is adapted from [this colab](https://colab.research.google.com/github/huggingface/datasets/blob/master/notebooks/Overview.ipynb) that presents an example of fine-tuning BertForQuestionAnswering using squad dataset. In that colab, loss works fine. When I adapt it to SST2, the loss fails to decrease as it should. I attach the adapted script below and appreciate anyone pointing out what I miss?

```python
import torch
from datasets import load_dataset
from transformers import BertForSequenceClassification
from transformers import BertTokenizerFast
# Load our training dataset and tokenizer
dataset = load_dataset("glue", 'sst2')
tokenizer = BertTokenizerFast.from_pretrained('bert-base-cased')
del dataset["test"] # let's remove it in this demo

# Tokenize our training dataset
def convert_to_features(example_batch):
    encodings = tokenizer(example_batch["sentence"])
    encodings.update({"labels": example_batch["label"]})
    return encodings

encoded_dataset = dataset.map(convert_to_features, batched=True)
# Format our dataset to outputs torch.Tensor to train a pytorch model
columns = ['input_ids', 'token_type_ids', 'attention_mask', 'labels']
encoded_dataset.set_format(type='torch', columns=columns)

# Instantiate a PyTorch Dataloader around our dataset
# Let's do dynamic batching (pad on the fly with our own collate_fn)
def collate_fn(examples):
    return tokenizer.pad(examples, return_tensors='pt')

dataloader = torch.utils.data.DataLoader(encoded_dataset['train'], collate_fn=collate_fn, batch_size=8)
# Now let's train our model
device = 'cuda' if torch.cuda.is_available() else 'cpu'
# Let's load a pretrained Bert model and a simple optimizer
model = BertForSequenceClassification.from_pretrained('bert-base-cased', return_dict=True)
optimizer = torch.optim.Adam(model.parameters(), lr=1e-5)
model.train().to(device)
for i, batch in enumerate(dataloader):
    batch.to(device)
    outputs = model(**batch)
    loss = outputs.loss
    loss.backward()
    optimizer.step()
    model.zero_grad()
    print(f'Step {i} - loss: {loss:.3}')


```
In case needed.

- datasets == 1.0.2
- transformers == 3.2.0

Comments: And I tested it on T5ForConditionalGeneration, that works no problem.

Hi did you manage to fix your issue ?

If so feel free to share your fix and close this thread
load_dataset from local squad.py, raise error: TypeError: 'NoneType' object is not callable 
State: closed | Author: xixiaoyao (NONE)


version: 1.0.2

```
train_dataset  = datasets.load_dataset('squad') 
```

The above code can works. However, when I download the squad.py from your server, and saved as `my_squad.py` to local. I run followings raise errors.
```
train_dataset  = datasets.load_dataset('./my_squad.py')                                                                                                
```
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-28-25a84b4d1581> in <module>
----> 1 train_dataset  = nlp.load_dataset('./my_squad.py')

/opt/conda/lib/python3.7/site-packages/datasets/load.py in load_dataset(path, name, data_dir, data_files, split, cache_dir, features, download_config, download_mode, ignore_verifications, save_infos, script_version, **config_kwargs)
    602         hash=hash,
    603         features=features,
--> 604         **config_kwargs,
    605     )
    606 

TypeError: 'NoneType' object is not callable


Comments: Hi !
Thanks for reporting.
It looks like no object inherits from `datasets.GeneratorBasedBuilder` (or more generally from `datasets.DatasetBuilder`) in your script.

Could you check that there exist at least one dataset builder class ?

Hi @xixiaoyao did you manage to fix your issue ?

No activity, closing

It happened when try to change the old project which use 'nlp' to new project which use 'datasets'. You should check you old 'my_squad.py' file, change the inherit class from `nlp.xxx` to `datasets.xxx`. Otherwise datasets - load.py - import_main_class() `if inspect.isclass(obj) and issubclass(obj, main_cls_type):` can not find the main_cls.
Squad Metric Description & Feature Mismatch
State: closed | Author: tshrjn (NONE)

The [description](https://github.com/huggingface/datasets/blob/master/metrics/squad/squad.py#L39) doesn't mention `answer_start` in squad. However the `datasets.features` require [it](https://github.com/huggingface/datasets/blob/master/metrics/squad/squad.py#L68). It's also not used in the evaluation.

Comments: Thanks for reporting !
There indeed a mismatch between the features and the kwargs description

I believe `answer_start` was added to match the squad dataset format for consistency, even though it is not used in the metric computation. I think I'd rather keep it this way, so that you can just give `references=squad["answers"]` to `.compute()`.
Maybe we can just fix the description then.

But then providing the `answer_start` becomes mandatory since the format of the features is checked against the one provided in the squad [file](https://github.com/huggingface/datasets/pull/658/files).
Use multiprocess from pathos for multiprocessing
State: closed | Author: lhoestq (MEMBER)

[Multiprocess](https://github.com/uqfoundation/multiprocess) (from the [pathos](https://github.com/uqfoundation/pathos) project) allows to use lambda functions in multiprocessed map.
It was suggested to use it by @kandorm.

We're already using dill which is its only dependency.

Comments: We can just install multiprocess actually, I'll change that

Just an FYI: I remember that I wanted to try pathos a couple of years back and I ran into issues considering cross-platform; the code would just break on Windows. If I can verify this PR by running CPU tests on Windows, let me know!

That's good to know thanks
I guess we can just wait for #644 to be merged first. I'm working on fixing the tests for windows

Looks like all the CI jobs on windows passed !
I also tested locally on my windows and it works great :) 

I think this is ready to merge, let me know if you have any remarks @thomwolf @BramVanroy
added Winogrande debiased subset
State: closed | Author: TevenLeScao (CONTRIBUTOR)

The [Winogrande](https://arxiv.org/abs/1907.10641) paper mentions a `debiased` subset that wasn't in the first release; this PR adds it.

Comments: To fix the CI you just have to copy the dummy data to the 1.1.0 folder, and maybe create the dummy ones for the `debiased` configuration

Fixed! Thanks @lhoestq
handle data alteration when trying type
State: closed | Author: lhoestq (MEMBER)

Fix #649 

The bug came from the type inference that didn't handle a weird case in Pyarrow.
Indeed this code runs without error but alters the data in arrow:
```python
import pyarrow as pa

type = pa.struct({"a": pa.struct({"b": pa.string()})})
array_with_altered_data = pa.array([{"a": {"b": "foo", "c": "bar"}}] * 10, type=type)
print(array_with_altered_data[0].as_py())
# {'a': {'b': 'foo'}} -> the sub-field "c" is missing
```
(I don't know if this is intended in pyarrow tbh)

We didn't take this case into account during type inference. By default it was keeping old features and maybe alter data.
To fix that I added a line that checks that the first element of the array is not altered.
Problem with JSON dataset format
State: open | Author: vikigenius (NONE)

I have a local json dataset with the following form.

{
    'id01234': {'key1': value1, 'key2': value2, 'key3': value3},
    'id01235': {'key1': value1, 'key2': value2, 'key3': value3},
    .
    .
    .
    'id09999': {'key1': value1, 'key2': value2, 'key3': value3}
}
Note that instead of a list of records it's basically a dictionary of key value pairs with the keys being the record_ids and the values being the corresponding record.

Reading this with json:

```
data = datasets.load('json', data_files='path_to_local.json')
```
Throws an error and asks me to chose a field. What's the right way to handle this?

Comments: Currently the `json` dataset doesn't support this format unfortunately.
However you could load it with
```python
from datasets import Dataset
import pandas as pd

df = pd.read_json("path_to_local.json", orient="index")
dataset = Dataset.from_pandas(df)
```

or you can make a custom dataset script as explained in doc here: https://huggingface.co/docs/datasets/add_dataset.html
dummy data testing can't test datasets using `dl_manager.extract` in `_split_generators`
State: closed | Author: richarddwang (CONTRIBUTOR)

Hi, I recently want to add a dataset whose source data is like this
```
openwebtext.tar.xz
  |__ openwebtext
         |__subset000.xz
         |     |__ ....txt
         |     |__ ....txt
         |     ...
         |__ subset001.xz
         |
         ....
```
So I wrote `openwebtext.py` like this
```
 def _split_generators(self, dl_manager):
        dl_dir = dl_manager.download_and_extract(_URL)
        owt_dir = os.path.join(dl_dir, 'openwebtext')
        subset_xzs = [
            os.path.join(owt_dir, file_name) for file_name in os.listdir(owt_dir) if file_name.endswith('xz') # filter out ...xz.lock
        ]
        ex_dirs = dl_manager.extract(subset_xzs, num_proc=round(os.cpu_count()*0.75))
        nested_txt_files = [ 
          [ 
            os.path.join(ex_dir,txt_file_name) for txt_file_name in os.listdir(ex_dir) if txt_file_name.endswith('txt')
          ] for ex_dir in ex_dirs
        ]
        txt_files = chain(*nested_txt_files)
        return [
            datasets.SplitGenerator(
                name=datasets.Split.TRAIN, gen_kwargs={"txt_files": txt_files}
            ),
        ]
```
All went good, I can load and use real openwebtext, except when I try to test with dummy data. The problem is  `MockDownloadManager.extract` do nothing, so `ex_dirs = dl_manager.extract(subset_xzs)` won't decompress `subset_xxx.xz`s for me.

How should I do ? Or you can modify `MockDownloadManager` to make it like a real `DownloadManager` ?

Comments: Hi :) 
In your dummy data zip file you can just have `subset000.xz` as directories instead of compressed files.
Let me know if it helps

Thanks for your comment @lhoestq ,
Just for confirmation, changing dummy data like this won't make dummy test test the functionality to extract `subsetxxx.xz` but actually kind of circumvent it. But since we will test the real data so it is ok ?

Yes it's fine for now. We plan to add a job for slow tests.
And at one point we'll also do another pass on the dummy data handling and consider extracting files.

Thanks for the confirmation.
Also the suggestion works. Thank you.
Inconsistent behavior in map
State: closed | Author: krandiash (NONE)
Labels: name: bug

I'm observing inconsistent behavior when applying .map(). This happens specifically when I'm incrementally adding onto a feature that is a nested dictionary. Here's a simple example that reproduces the problem.

```python
import datasets

# Dataset with a single feature called 'field' consisting of two examples
dataset = datasets.Dataset.from_dict({'field': ['a', 'b']})
print(dataset[0])
# outputs
{'field': 'a'}

# Map this dataset to create another feature called 'otherfield', which is a dictionary containing a key called 'capital'
dataset = dataset.map(lambda example: {'otherfield': {'capital': example['field'].capitalize()}})
print(dataset[0])
# output is okay
{'field': 'a', 'otherfield': {'capital': 'A'}}

# Now I want to map again to modify 'otherfield', by adding another key called 'append_x' to the dictionary under 'otherfield'
print(dataset.map(lambda example: {'otherfield': {'append_x': example['field'] + 'x'}})[0])
# printing out the first example after applying the map shows that the new key 'append_x' doesn't get added
# it also messes up the value stored at 'capital'
{'field': 'a', 'otherfield': {'capital': None}}

# Instead, I try to do the same thing by using a different mapped fn
print(dataset.map(lambda example:  {'otherfield': {'append_x': example['field'] + 'x', 'capital': example['otherfield']['capital']}})[0])
# this preserves the value under capital, but still no 'append_x'
{'field': 'a', 'otherfield': {'capital': 'A'}}

# Instead, I try to pass 'otherfield' to remove_columns
print(dataset.map(lambda example:  {'otherfield': {'append_x': example['field'] + 'x', 'capital': example['otherfield']['capital']}}, remove_columns=['otherfield'])[0])
# this still doesn't fix the problem
{'field': 'a', 'otherfield': {'capital': 'A'}}

# Alternately, here's what happens if I just directly map both 'capital' and 'append_x' on a fresh dataset.

# Recreate the dataset
dataset = datasets.Dataset.from_dict({'field': ['a', 'b']})
# Now map the entire 'otherfield' dict directly, instead of incrementally as before
print(dataset.map(lambda example:  {'otherfield': {'append_x': example['field'] + 'x', 'capital': example['field'].capitalize()}})[0])
# This looks good!
{'field': 'a', 'otherfield': {'append_x': 'ax', 'capital': 'A'}}
```

This might be a new issue, because I didn't see this behavior in the `nlp` library. 

Any help is appreciated!

Comments: Thanks for reporting !

This issue must have appeared when we refactored type inference in `nlp`
By default the library tries to keep the same feature types when applying `map` but apparently it has troubles with nested structures. I'll try to fix that next week
Cannot download dataset_info.json
State: closed | Author: chiyuzhang94 (NONE)

I am running my job on a cloud server where does not provide for connections from the standard compute nodes to outside resources. Hence, when I use `dataset.load_dataset()` to load data, I got an error like this:

```
ConnectionError: Couldn't reach https://storage.googleapis.com/huggingface-nlp/cache/datasets/text/default-53ee3045f07ba8ca/0.0.0/dataset_info.json
```

I tried to open this link manually, but I cannot access this file. How can I download this file and pass it through `dataset.load_dataset()` manually?

Versions:
Python version 3.7.3
PyTorch version 1.6.0
TensorFlow version 2.3.0
datasets version: 1.0.1 


Comments: Thanks for reporting !
We should add support for servers without internet connection indeed
I'll do that early next week

Thanks, @lhoestq !
Please let me know when it is available. 

Right now the recommended way is to create the dataset on a server with internet connection and then to save it and copy the serialized dataset to the server without internet connection.

#652 should allow you to load text/json/csv/pandas datasets without an internet connection **IF** you've the dataset script locally.

Example: 
If you have `datasets/text/text.py` locally, then you can do `load_dataset("./datasets/text", data_files=...)`
Fix docs typos
State: closed | Author: mariosasko (COLLABORATOR)

This PR fixes few typos in the docs and the error in the code snippet in the set_format section in docs/source/torch_tensorflow.rst. `torch.utils.data.Dataloader` expects padded batches so it throws an error due to not being able to stack the unpadded tensors. If we follow the Quick tour from the docs where they add the `truncation=True, padding='max_length'` arguments to the tokenizer before passing data to Dataloader, we can easily fix the issue.
Don't use take on dataset table in pyarrow 1.0.x
State: closed | Author: lhoestq (MEMBER)

Fix #615 

Comments: I tried lower batch sizes and it didn't accelerate filter (quite the opposite actually).
The slow-down also appears for pyarrow 0.17.1 for some reason, not sure it comes from these changes

I just checked the benchmarks of other PRs and some of them had 300s (!!) for filter. This needs some investigation..

Merging this one since it's not the cause of the the slow down

@lhoestq What might be the reason for the slowdown? When I was training large batchsize, the slowdown was obvious, and my original assumption was to increase write_batch_size
Better windows support
State: closed | Author: lhoestq (MEMBER)

There are a few differences in the behavior of python and pyarrow on windows.

For example there are restrictions when accessing/deleting files that are open

Fix #590 

Comments: This PR is ready :)
It brings official support for windows.

Some tests `AWSDatasetTest` are failing.
This is because I had to fix a few datasets that were not compatible with windows.
These test will pass once they got merged on master :)
Add Polyglot-NER Dataset
State: closed | Author: joeddav (CONTRIBUTOR)

Adds the [Polyglot-NER dataset](https://sites.google.com/site/rmyeid/projects/polylgot-ner) with named entity tags for 40 languages. I include separate configs for each language as well as a `combined` config which lumps them all together.

Comments: Hi @joeddav thanks for adding this! (I did a long webarchive.org session to actually find that dataset a while ago).

One question: should we manually correct the labeling scheme to (at least) IOB1?

That means "LOC" will be converted to "I-LOC". IOB1 is not explict. mentioned in the paper, but it is used in the documentation:

https://polyglot.readthedocs.io/en/latest/NamedEntityRecognition.html

@stefan-it I went back and forth on this. My biggest problem with it is that once you are in IOB, there is the expectation that the beginning of new entities are marked with a `B-` (at least in the case of two back-to-back entities):
```
Today    O
Alice    I-PER
Bob      B-PER
and      O
I        O 
ate      O
lasagna  O
```
If we just prepend `I-` to everything, `Bob` would be incorrectly tagged `I-PER`, meaning `Bob Alice` is a single entity. The current format is bad but is at least clear that it does not contain that information.

But I could go either way if someone has a strong opinion.

Indeed I'm not sure we can convert them to IOB because of this issue. I'm fine with keeping it like that

I'll do a release later today, hopefully we can include this dataset in the release :)

Let me know if you need help with the dummy data

@lhoestq cool thanks, I think I've got it right now – just zipped them wrong. I'm running tests locally now and then will push.

@lhoestq set to merge?

@joeddav I'm fine with keeping the original labeling scheme :)
GLUE/QQP dataset: NonMatchingChecksumError
State: closed | Author: richarddwang (CONTRIBUTOR)

Hi @lhoestq , I know you are busy and there are also other important issues. But if this is easy to be fixed, I am shamelessly wondering if you can give me some help , so I can evaluate my models and restart with my developing cycle asap. 😚

datasets version: editable install of master at 9/17

`datasets.load_dataset('glue','qqp', cache_dir='./datasets')`

```
Downloading and preparing dataset glue/qqp (download: 57.73 MiB, generated: 107.02 MiB, post-processed: Unknown size, total: 164.75 MiB) to ./datasets/glue/qqp/1.0.0/7c99657241149a24692c402a5c3f34d4c9f1df5ac2e4c3759fadea38f6cb29c4...
---------------------------------------------------------------------------
NonMatchingChecksumError                  Traceback (most recent call last)
 in 
----> 1 datasets.load_dataset('glue','qqp', cache_dir='./datasets')

~/datasets/src/datasets/load.py in load_dataset(path, name, data_dir, data_files, split, cache_dir, features, download_config, download_mode, ignore_verifications, save_infos, script_version, **config_kwargs)
    609         download_config=download_config,
    610         download_mode=download_mode,
--> 611         ignore_verifications=ignore_verifications,
    612     )
    613 

~/datasets/src/datasets/builder.py in download_and_prepare(self, download_config, download_mode, ignore_verifications, try_from_hf_gcs, dl_manager, **download_and_prepare_kwargs)
    467                     if not downloaded_from_gcs:
    468                         self._download_and_prepare(
--> 469                             dl_manager=dl_manager, verify_infos=verify_infos, **download_and_prepare_kwargs
    470                         )
    471                     # Sync info

~/datasets/src/datasets/builder.py in _download_and_prepare(self, dl_manager, verify_infos, **prepare_split_kwargs)
    527         if verify_infos:
    528             verify_checksums(
--> 529                 self.info.download_checksums, dl_manager.get_recorded_sizes_checksums(), "dataset source files"
    530             )
    531 

~/datasets/src/datasets/utils/info_utils.py in verify_checksums(expected_checksums, recorded_checksums, verification_name)
     37     if len(bad_urls) > 0:
     38         error_msg = "Checksums didn't match" + for_verification_name + ":\n"
---> 39         raise NonMatchingChecksumError(error_msg + str(bad_urls))
     40     logger.info("All the checksums matched successfully" + for_verification_name)
     41 

NonMatchingChecksumError: Checksums didn't match for dataset source files:
['https://dl.fbaipublicfiles.com/glue/data/QQP-clean.zip']
```

Comments: Hi ! Sure I'll take a look
Fix text delimiter
State: closed | Author: lhoestq (MEMBER)

I changed the delimiter in the `text` dataset script.
It should fix the `pyarrow.lib.ArrowInvalid: CSV parse error` from #622 

I changed the delimiter to an unused ascii character that is not present in text files : `\b`

Comments: Which OS are you using ?@abhi1nandy2

> Which OS are you using ?

PRETTY_NAME="Debian GNU/Linux 9 (stretch)"
NAME="Debian GNU/Linux"
VERSION_ID="9"
VERSION="9 (stretch)"
VERSION_CODENAME=stretch
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"

Do you mind sharing the data you used (or part of it), so I can try to reproduce ?
Or at least some info about the text file you're using ? (size, n of lines, encoding)

Lot of data, difficult to share. There are 46 shards, each having about 256000 lines. using `file` command gives this - `ASCII text, with very long lines`.

Ok I see, no problem :) 
I'll see what I can do

Could you just test with one single dummy text file with a few lines to see if you're having the issue ?
Also which version of `datasets` do you have ?