helmo/github-issues huggingface dataset:
Streaming with num_workers != 0
State: closed | Author: justheuristic (NONE)
Labels: name: bug

## Describe the bug
When using dataset streaming with pytorch DataLoader, the setting num_workers to anything other than 0 causes the code to freeze forever before yielding the first batch.

The code owner is likely @lhoestq 

## Steps to reproduce the bug

For your convenience, we've prepped a colab notebook that reproduces the bug
https://colab.research.google.com/drive/1Mgl0oTZSNIE3UeGl_oX9wPCOIxRg19h1?usp=sharing
```python
!pip install datasets==1.14.0

should_freeze_forever = True
# ^-- set this to True in order to freeze forever, set to False in order to work normally

import torch
from datasets import load_dataset

data = load_dataset("oscar", "unshuffled_deduplicated_bn", split="train", streaming=True)
data = data.map(lambda x: {"text": x["text"], "orig": f"oscar[{x['id']}]"}, batched=True)
data = data.shuffle(100, seed=1337)

data = data.with_format("torch")
loader = torch.utils.data.DataLoader(data, batch_size=2, num_workers=2 if should_freeze_forever else 0)

# v-- the code should freeze forever at this line
for i, row in enumerate(loader):
  print(row)
  if i > 10: break
print("DONE!")
```

## Expected results
The code should not freeze forever with num_workers=2

## Actual results
The code freezes forever with num_workers=2

## Environment info
- `datasets` version: 1.14.0 (also found in previous versions)
- Platform: google colab (also locally)
- Python version: 3.7, (also 3.8)
- PyArrow version: 3.0.0



Comments: I can confirm that I was able to reproduce the bug. This seems odd given that #3423 reports duplicate data retrieval when `num_workers` and `streaming` are used together, which is obviously different from what is reported here. 

Any update? A possible solution is to have multiple arrow files as shards, and handle them like what webdatasets does.
![image](https://user-images.githubusercontent.com/11533479/148176637-72746b2c-c122-47aa-bbfe-224b13ee9a71.png)

Pytorch's new dataset RFC is supporting sharding now, which may helps avoid duplicate data under streaming mode. (https://github.com/pytorch/pytorch/blob/master/torch/utils/data/datapipes/iter/grouping.py#L13)


Hi ! Thanks for the insights :) Note that in streaming mode there're usually no arrow files. The data are streamed from TAR, ZIP, text, etc. files directly from the web. Though for sharded datasets we can definitely adopt a similar strategy !

fixed by #4375
CLI test command throws NonMatchingSplitsSizesError when saving infos
State: closed | Author: albertvillanova (MEMBER)
Labels: name: bug

When trying to generate a datset JSON metadata, a `NonMatchingSplitsSizesError` is thrown:
```
$ datasets-cli test datasets/arabic_billion_words --save_infos --all_configs
Testing builder 'Alittihad' (1/10)
Downloading and preparing dataset arabic_billion_words/Alittihad (download: 332.13 MiB, generated: Unknown size, post-processed: Unknown size, total: 332.13 MiB) to .cache\arabic_billion_words\Alittihad\1.1.0\8175ff1c9714c6d5d15b1141b6042e5edf048276bb81a9c14e35e149a7a62ae4...
Traceback (most recent call last):
  File "path\huggingface\datasets\.venv\Scripts\datasets-cli-script.py", line 33, in <module>
    sys.exit(load_entry_point('datasets', 'console_scripts', 'datasets-cli')())
  File "path\huggingface\datasets\src\datasets\commands\datasets_cli.py", line 33, in main
    service.run()
  File "path\huggingface\datasets\src\datasets\commands\test.py", line 144, in run
    builder.download_and_prepare(
  File "path\huggingface\datasets\src\datasets\builder.py", line 607, in download_and_prepare
    self._download_and_prepare(
  File "path\huggingface\datasets\src\datasets\builder.py", line 709, in _download_and_prepare
    verify_splits(self.info.splits, split_dict)
  File "path\huggingface\datasets\src\datasets\utils\info_utils.py", line 74, in verify_splits
    raise NonMatchingSplitsSizesError(str(bad_splits))
datasets.utils.info_utils.NonMatchingSplitsSizesError: [{'expected': SplitInfo(name='train', num_bytes=0, num_examples=0, dataset_name='arabic_billion_words'), 'recorded': SplitInfo(name='train', num_bytes=1601790302, num_examples=349342, dataset_name='arabic_billion_words')}]
```

This is due because a previous run generated a wrong `dataset_info.json`.

This error can be avoided by passing `--ignore_verifications`, but I think this should be assumed when passing `--save_infos`.
[when Image type will exist] provide a way to get the data as binary + filename
State: closed | Author: severo (COLLABORATOR)
Labels: name: enhancement

name: dataset-viewer

**Is your feature request related to a problem? Please describe.**

When a dataset cell contains a value of type Image (be it from a remote URL, an Array2D/3D, or any other way to represent images), I want to be able to write the image to the disk, with the correct filename, and optionally to know its mimetype, in order to serve it on the web.

Note: this issue would apply exactly the same for the `Audio` type.

**Describe the solution you'd like**

If a "cell" has the type `Image`, provide a way to get the binary content of the file, and the filename, eg as:

```python
  filename: str
  data: bytes
```

**Describe alternatives you've considered**

A way to write the cell to the disk (passing a local directory), and then return the pathname, filename, and mimetype.


Comments: @severo, maybe somehow related to this PR ?
- #3129

@severo I'll keep that in mind.

You can track progress on the Image feature in #3163 (still in the early stage).  

Hi ! As discussed with @severo offline it looks like the dataset viewer already supports reading PIL images, so maybe the dataset viewer doesn't need to disable decoding after all

Fixed with https://github.com/huggingface/datasets/pull/3163
Infer the features if missing
State: closed | Author: severo (COLLABORATOR)
Labels: name: enhancement

name: dataset-viewer

**Is your feature request related to a problem? Please describe.**

Some datasets, in particular community datasets, have no info file, thus no features.

**Describe the solution you'd like**

If a dataset has no features, the first loaded data (5-10 rows) could be used to infer the type.

Related: `datasets` would provide a way to load the data, and get the rows AND the features as the result.

**Describe alternatives you've considered**

The HF hub could also provide some UI to help the dataset maintainers to explicit the types of their rows, or automatically infer them as an initial proposal.

Comments: Done by @lhoestq here: https://github.com/huggingface/datasets/pull/4500 (https://github.com/huggingface/datasets/pull/4500/files#diff-02930e1d966f4b41f9ddf15d961f16f5466d9bee583138657018c7329f71aa43R1255 in particular)
Provide a way to check if the features (in info) match with the data of a split
State: open | Author: severo (COLLABORATOR)
Labels: name: enhancement

name: dataset-viewer

**Is your feature request related to a problem? Please describe.**

I understand that currently the data loaded has not always the type described in the info features

**Describe the solution you'd like**

Provide a way to check if the rows have the type described by info features

**Describe alternatives you've considered**

Always check it, and raise an error when loading the data if their type doesn't match the features.


Comments: Related: #3144
Provide a way to write a streamed dataset to the disk
State: open | Author: severo (COLLABORATOR)
Labels: name: enhancement

name: dataset-viewer

**Is your feature request related to a problem? Please describe.**

The streaming mode allows to get the 100 first rows of a dataset very quickly. But it does not cache the answer, so a posterior call to get the same 100 rows will send a request to the server again and again.

**Describe the solution you'd like**

Provide a way to write the streamed rows of a dataset on the disk, and to load from it later.

**Describe alternatives you've considered**

Provide a third mode: `lazy`, which would use the local cache for the data that have already been fetched previously, and use streaming to get the rest of the requested data. 


Comments: Yes, I agree this feature is much needed. We could do something similar to what TF does (https://www.tensorflow.org/api_docs/python/tf/data/Dataset#cache). 

Ideally, if the entire streamed dataset is consumed/cached, the generated cache should be reusable for the Arrow dataset.

@mariosasko Hi big brother,any update on this? It's 2024 with large streamed dataset loading consume too much time(exp.  2day..), really need this feature for what TF does
Fix file/directory deletion on Windows  
State: open | Author: mariosasko (COLLABORATOR)
Labels: name: bug

Currently, on Windows, some attempts to delete a dataset file/directory will fail with the `PerimissionError`. 

Examples:
- download a dataset, then force redownload it in the same session while keeping a reference to the downloaded dataset
```python
from datasets import load_dataset
dset = load_dataset("sst", split="train")
dset = load_dataset("sst", split="train", download_mode="force_redownload")
```
- try to clean up the cache files while keeping a reference to those files (via the mapped dataset):
```python
from datasets import load_dataset
dset = load_dataset("sst", split="train")
dset_mapped = dset.map(lambda _: {"dummy_col": 1})
dset.cleanup_cache_files()
```
We should fix those.
More fine-grained taxonomy of error types
State: open | Author: severo (COLLABORATOR)
Labels: name: enhancement

name: dataset-viewer

**Is your feature request related to a problem? Please describe.**

Exceptions like `FileNotFoundError` can be raised by different parts of the code, and it's hard to detect which one did

**Describe the solution you'd like**

Give a specific exception type for every group of similar errors

**Describe alternatives you've considered**

Rely on the error message, using regex


Comments: related: #4995
Fix numpy deprecation warning for ragged tensors
State: closed | Author: lhoestq (MEMBER)

Numpy shows a deprecation warning when we call `np.array` on a list of ragged tensors without specifying the `dtype`. If their shapes match, the tensors can be collated together, otherwise the resulting array should have `dtype=np.object`.

Fix #3084 
cc @Rocketknight1 

Comments: This'll be a really helpful fix, thank you!
Fix script of Arabic Billion Words dataset to return all data
State: closed | Author: albertvillanova (MEMBER)

The script has a bug and only parses and generates a portion of the entire dataset.

This PR fixes the loading script so that is properly parses the entire dataset. 

Current implementation generates the same number of examples as reported in the [original paper](https://arxiv.org/abs/1611.04033) for all configurations except for one:
- For "Youm7" we generate more examples (1172136) than the ones reported by the paper (1025027)

|                | Number of examples | Number of examples according to the source |
|:---------------|-------------------:|-----:|
| Alittihad      |             349342 |349342 |
| Almasryalyoum  |             291723 |291723 |
| Almustaqbal    |             446873 |446873 |
| Alqabas        |             817274 |817274 |
| Echoroukonline |             139732 |139732 |
| Ryiadh         |             858188 | 858188 |
| Sabanews       |              92149 |92149 |
| SaudiYoum      |             888068 |888068 |
| Techreen       |             314597 |314597 |
| Youm7          |            1172136 |1025027 |

Fix #3126.
Make inspect.get_dataset_config_names always return a non-empty list of configs
State: closed | Author: severo (COLLABORATOR)
Labels: name: enhancement

name: dataset-viewer

**Is your feature request related to a problem? Please describe.**

Currently, some datasets have a configuration, while others don't. It would be simpler for the user to always have configuration names to refer to

**Describe the solution you'd like**

In that sense inspect.get_dataset_config_names should always return at least one configuration name, be it `default` or `Check___region_1` (for community datasets like `Check/region_1`).

https://github.com/huggingface/datasets/blob/c5747a5e1dde2670b7f2ca6e79e2ffd99dff85af/src/datasets/inspect.py#L161


Comments: Hi @severo, I guess this issue requests not only to be able to access the configuration name (by using `inspect.get_dataset_config_names`), but the configuration itself as well (I mean you use the name to get the configuration afterwards, maybe using `builder_cls.builder_configs`), is this right?

Yes, maybe the issue could be reformulated. As a user, I want to avoid having to manage special cases:
- I want to be able to get the names of a dataset's configs, and use them in the rest of the API (get the data, get the split names, etc).
- I don't want to have to manage datasets with named configs (`glue`) differently from datasets without named configs (`acronym_identification`, `Check/region_1`)
Add ADE20k
State: closed | Author: NielsRogge (CONTRIBUTOR)
Labels: name: dataset request

name: vision

## Adding a Dataset
- **Name:** ADE20k (actually it's called the MIT Scene Parsing Benchmark, it's actually a subset of ADE20k but a lot of authors still call it ADE20k)
- **Description:** A semantic segmentation dataset, consisting of 150 classes.
- **Paper:** http://people.csail.mit.edu/bzhou/publication/scene-parse-camera-ready.pdf
- **Data:** http://sceneparsing.csail.mit.edu/
- **Motivation:** I am currently adding Transformer-based semantic segmentation models that achieve SOTA on this dataset. It would be great to directly access this dataset using HuggingFace Datasets, in order to make example scripts in HuggingFace Transformers.

Instructions to add a new dataset can be found [here](https://github.com/huggingface/datasets/blob/master/ADD_NEW_DATASET.md).


Comments: I think we can close this issue since PR [#3607](https://github.com/huggingface/datasets/pull/3607) solves this.
Support Audio feature for TAR archives in sequential access
State: closed | Author: albertvillanova (MEMBER)

Add Audio feature support for TAR archived files in sequential access.

Fix #3128.

Comments: Also do you think we can adapt `cast_column` to keep the same value for this new parameter when the user only wants to change the sampling rate ?

Thanks for your comments, @lhoestq, I will address them afterwards.

But, I think it is more important/urgent first address the current blocking non-passing test: https://github.com/huggingface/datasets/runs/4143579241?check_suite_focus=true
- I am thinking of a way of solving it, but if you have any hint, it will be more than welcome! 😅 

Basically:
```
{'audio': '/tmp/pytest-of-runner/pytest-0/popen-gw1/test_dataset_with_audio_featur1/data/test_audio_44100.wav'}
``` 
becomes
```
{'audio': {'bytes': None, 'path': '/tmp/pytest-of-runner/pytest-0/popen-gw1/test_dataset_with_audio_featur1/data/test_audio_44100.wav'}}
```
after a `map`, which is what was stored in the Arrow file. However we expect it remains invariant after this `map`.

@lhoestq, @mariosasko I finally proposed another implementation different from my last one:
- Before: store Audio always a struct<path: string, bytes: binary>, where bytes can be None
- Now, depending on the examples, either store Audio as a struct (as before), or as a string.

Please note that the main motivation for this change was the issue mentioned above: https://github.com/huggingface/datasets/pull/3129#issuecomment-964347056


Until here we had the assumption that a Features object always has an associated, deterministic, pyarrow schema. This is useful to ensure that we are able to concatenate two datasets that have the same features for example.

By breaking this assumption for the Audio type, how can we ensure that we can concatenate two audio datasets if one has Audio as a struct and the other a string ?

Oh I noticed that the Audio feature type has a private attribute `_storage_dtype`, so the assumption still holds, since they are now different feature types depending on the this attribute :)
(i mean different from the python equal operator point of view)

I think this PR is ready, @lhoestq, @mariosasko.  

Nit: We should also mention the new storage structure in the `Features` docstring [here](https://github.com/huggingface/datasets/blob/b29fb550c31de337b952035a7584147e0f18c0cf/src/datasets/features/features.py#L966) for users to know what type of value to return in their dataset scripts (we also have a link to that docstring in the `ADD_NEW_DATASET` template).
datasets-cli: convertion of a tfds dataset to a huggingface one.
State: open | Author: vitalyshalumov (NONE)

### Discussed in https://github.com/huggingface/datasets/discussions/3079

<div type='discussions-op-text'>

<sup>Originally posted by **vitalyshalumov** October 14, 2021</sup>
I'm trying to convert a tfds dataset to a huggingface one.

I've tried:

1.       datasets-cli convert  --tfds_path ~/tensorflow_datasets/mnist/3.0.1/ --datasets_directory ~/.cache/huggingface/datasets/mnist/3.0.1/

2.       datasets-cli convert  --tfds_path ~/tensorflow_datasets/mnist/3.0.1/ --datasets_directory ~/.cache/huggingface/datasets/


and other permutations.
The script appears to be running and finishing without an error but when looking in the  huggingface/datasets/ folder nothing is created.


</div>

Comments: Hi,

the MNIST dataset is already available on the Hub. You can use it as follows:
```python
import datasets
dataset_dict = datasets.load_dataset("mnist")
```

As for the conversion of TFDS datasets to HF datasets, we will be working on it in the coming months, so stay tuned.
"arabic_billion_words" dataset does not create the full dataset
State: closed | Author: vitalyshalumov (NONE)
Labels: name: bug

## Describe the bug
When running: 
raw_dataset = load_dataset('arabic_billion_words','Alittihad')
the correct dataset file is pulled from the url.
But, the generated dataset includes just a small portion of the data included in the file.
This is true for all other portions of the "arabic_billion_words" dataset ('Almasryalyoum',.....)

## Steps to reproduce the bug
```python
# Sample code to reproduce the bug
raw_dataset = load_dataset('arabic_billion_words','Alittihad')

#The screen message
Downloading and preparing dataset arabic_billion_words/Alittihad (download: 332.13 MiB, generated: 20.62 MiB, post-processed: Unknown size, total: 352.74 MiB) 

## Expected results
over 100K sentences

## Actual results
only 11K sentences

## Environment info
<!-- You can run the command `datasets-cli env` and copy-and-paste its output below. -->
- `datasets` version: 1.14.0
- Platform: Linux-5.8.0-63-generic-x86_64-with-glibc2.29
- Python version: 3.8.10
- PyArrow version: 4.0.1



Comments: Thanks for reporting, @vitalyshalumov.

Apparently the script to parse the data has a bug, and does not generate the entire dataset.

I'm fixing it.
More efficient nested features encoding
State: closed | Author: eladsegal (CONTRIBUTOR)

Nested encoding of features wastes a lot of time on operations which are effectively doing nothing when lists are used.
For example, if in the input we have a list of integers, `encoded_nested_example` will iterate over it and apply `encoded_nested_example` on every element even though it just return the int as is.

A similar issue is handled at an earlier stage when casting pytorch/tensorflow/pandas objects to python lists/numpy arrays:
https://github.com/huggingface/datasets/blob/c98c23c4260edadab00f997d1a5d66b7f2e93ce9/src/datasets/features/features.py#L149-L156
https://github.com/huggingface/datasets/blob/c98c23c4260edadab00f997d1a5d66b7f2e93ce9/src/datasets/features/features.py#L212-L228

In this pull request I suggest to use the same approach in `encoded_nested_example`.
In my setup there was a major speedup with this change: loading the data was at least x4 faster. 

Comments: @lhoestq @albertvillanova @mariosasko
Can you please check this out?

Thanks, done!
Segmentation fault when loading datasets from file
State: closed | Author: TevenLeScao (CONTRIBUTOR)
Labels: name: bug

## Describe the bug
Custom dataset loading sometimes segfaults and kills the process if chunks contain a variety of features/

## Steps to reproduce the bug

Download an example file:
```
wget https://gist.githubusercontent.com/TevenLeScao/11e2184394b3fa47d693de2550942c6b/raw/4232704d08fbfcaf93e5b51def9e5051507651ad/tiny_kelm.jsonl
```
Then in Python:
```
import datasets
tiny_kelm = datasets.load_dataset("json", data_files="tiny_kelm.jsonl", chunksize=100000)
```

## Expected results
a `tiny_kelm` functional dataset

## Actual results
☠️ `Segmentation fault (core dumped)` ☠️

## Environment info
- `datasets` version: 1.14.0
- Platform: Linux-5.11.0-38-generic-x86_64-with-glibc2.29
- Python version: 3.8.10
- PyArrow version: 5.0.0

Comments: Hi ! I created an issue on Arrow's JIRA after making a minimum reproducible example

https://issues.apache.org/jira/browse/ARROW-14439

```python
import io

import pyarrow.json as paj

batch = b'{"a": [], "b": 1}\n{"b": 1}'
block_size = 12

paj.read_json(
    io.BytesIO(batch), read_options=paj.ReadOptions(block_size=block_size)
)
```

I don't see a way to workaround this properly now without hurting the performance of the JSON loader significantly though

The issue has been fixed in pyarrow 6.0.0, please update pyarrow :)

The issue was due to missing fields in the JSON data of type list. Now it's working fine and missing list fields are replaced with empty lists
Use huggingface_hub.HfApi to list datasets/metrics
State: closed | Author: mariosasko (COLLABORATOR)

Delete `datasets.inspect.HfApi` and use `huggingface_hub.HfApi` instead.

WIP until https://github.com/huggingface/huggingface_hub/pull/429 is merged, then wait for the new release of  `huggingface_hub`, update the `huggingface_hub` version in `setup.py` and merge this PR.

cc: @lhoestq
Correctly update metadata to preserve features when concatenating datasets with axis=1
State: closed | Author: mariosasko (COLLABORATOR)

This PR correctly updates metadata to preserve higher-level feature types (e.g. `ClassLabel`) in `datasets.concatenate_datasets` when `axis=1`. Previously, we would delete the feature metadata in `datasets.concatenate_datasets` if `axis=1` and restore the feature types from the arrow table schema in `Dataset.__init__`. However, this approach only works for simple feature types (e.g. `Value`).

Fixes #3111
Add OpenSLR 83 - Crowdsourced high-quality UK and Ireland English Dialect speech
State: closed | Author: tyrius02 (CONTRIBUTOR)
Labels: name: dataset request

## Adding a Dataset
- **Name:** *openslr**
- **Description:** *Data set which contains male and female recordings of English from various dialects of the UK and Ireland.*
- **Paper:** *https://www.openslr.org/resources/83/about.html*
- **Data:** *Eleven separate data files can be found via https://www.openslr.org/resources/83/*
- **Motivation:** *Increase english ASR data with UK and Irish dialects*

Instructions to add a new dataset can be found [here](https://github.com/huggingface/datasets/blob/master/ADD_NEW_DATASET.md).

The *openslr* dataset already exists, this will add additional subset, *SLR83*.

Comments: Ugh. The index files for SLR83 are CSV, not TSV. I need to add logic to process these index files.