Raibek/github-issues huggingface dataset:
support for custom feature encoding/decoding

Fix for https://github.com/huggingface/datasets/issues/7220 as suggested in discussion, in preference to #7221 

(only concern would be on effect on type checking with custom feature types that aren't covered by FeatureType?)
Add filename in error message when ReadError or similar occur

Please update error messages to include relevant information for debugging when loading datasets with `load_dataset()` that may have a few corrupted files. 

Whenever downloading a full dataset, some files might be corrupted (either at the source or from downloading corruption). 

However the errors often only let me know it was a tar file if `tarfile.ReadError` appears on the traceback, and I imagine similarly for other file types. 

This makes it really hard to debug which file is corrupted, and when dealing with very large datasets, it shouldn't be necessary to force download everything again.
Raise error for incorrect JSON serialization

Raise error when `lines = False` and `batch_size < Dataset.num_rows` in `Dataset.to_json()`.

Issue: #7037 

Related PRs:
#7039 #7181 

PTAL @lhoestq @albertvillanova
Memory leak when streaming

### Describe the bug

I try to use a dataset with streaming=True, the issue I have is that the RAM usage becomes higher and higher until it is no longer sustainable.

I understand that huggingface store data in ram during the streaming, and more worker in dataloader there are, more a lot of shard will be stored in ram, but the issue I have is that the ram usage is not constant. So after each new shard loaded, the ram usage will be higher and higher.

### Steps to reproduce the bug

You can run this code and see you ram usage, after each shard of 255 examples, your ram usage will be extended.
```py
from datasets import load_dataset
from torch.utils.data import DataLoader

dataset = load_dataset("WaveGenAI/dataset", streaming=True)

dataloader = DataLoader(dataset["train"], num_workers=3)

for i, data in enumerate(dataloader):
    print(i, end="\r")
```

### Expected behavior

The Ram usage should be always the same (just 3 shards loaded in the ram).

### Environment info

- `datasets` version: 3.0.1
- Platform: Linux-6.10.5-arch1-1-x86_64-with-glibc2.40
- Python version: 3.12.4
- `huggingface_hub` version: 0.26.0
- PyArrow version: 17.0.0
- Pandas version: 2.2.3
- `fsspec` version: 2024.6.1

I seem to have encountered the same problem when loading non streaming datasets. load_from_disk. Causing hundreds of GB of memory, but the dataset actually only has 50GB
load_from_disk

### Describe the bug

I have data saved with save_to_disk. The data is big (700Gb). When I try loading it, the only option is load_from_disk, and this function copies the data to a tmp directory, causing me to run out of disk space. Is there an alternative solution to that?

### Steps to reproduce the bug

when trying to load data using load_From_disk after being saved using save_to_disk 

### Expected behavior

run out of disk space

### Environment info

lateest version

Hello, It's an interesting issue here. I have the same problem, I have a local dataset and I want to push the dataset to the hub but huggingface does a copy of it.

```py
from datasets import load_dataset

dataset = load_dataset("webdataset", data_files="/media/works/data/*.tar") # copy here
dataset.push_to_hub("WaveGenAI/audios2")
```

Edit: I can use HfApi for my use case
Cannot load the cache when mapping the dataset

### Describe the bug

I'm training the flux controlnet. The train_dataset.map() takes long time to finish. However, when I killed one training process and want to restart a new training with the same dataset. I can't reuse the mapped result even I defined the cache dir for the dataset.

with accelerator.main_process_first():
        from datasets.fingerprint import Hasher

        # fingerprint used by the cache for the other processes to load the result
        # details: https://github.com/huggingface/diffusers/pull/4038#discussion_r1266078401
        new_fingerprint = Hasher.hash(args)
        train_dataset = train_dataset.map(
            compute_embeddings_fn, batched=True, new_fingerprint=new_fingerprint, batch_size=10,
        )

### Steps to reproduce the bug

train flux controlnet and start again



### Expected behavior

will not map again

### Environment info

latest diffusers
cache can't cleaned or disabled

### Describe the bug

I tried following ways, the cache can't be disabled. 

I got 2T data, but I also got more than 2T cache file. I got pressure on storage. I need to diable cache or cleaned immediately after processed. Following ways are all not working, please give some help!

```python
from datasets import disable_caching
from transformers import AutoTokenizer
disable_caching()

tokenizer = AutoTokenizer.from_pretrained(args.tokenizer_path)
def tokenization_fn(examples):
    column_name = 'text' if 'text' in examples else 'data'
    tokenized_inputs = tokenizer(
        examples[column_name], return_special_tokens_mask=True, truncation=False,
        max_length=tokenizer.model_max_length
    )
    return tokenized_inputs

data = load_dataset('json', data_files=save_local_path, split='train', cache_dir=None)
data.cleanup_cache_files()
updated_dataset = data.map(tokenization_fn, load_from_cache_file=False)
updated_dataset .cleanup_cache_files()
```

### Expected behavior

no cache file generated

### Environment info

Ubuntu 20.04.6 LTS
datasets  3.0.2
Add IterableDataset.shard()

Will be useful to distribute a dataset across workers (other than pytorch) like spark

I also renamed `.n_shards` -> `.num_shards` for consistency and kept the old name for backward compatibility. And a few changes in internal functions for consistency as well (rank, world_size -> num_shards, index)

Breaking change: the new default for `contiguous` in `Dataset.shard()` is `True`, but imo not a big deal since I couldn't find any usage of `contiguous=False` internally (we always do contiguous=True for map-style datasets since its more optimized) or in the wild

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/datasets/pr_7252). All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.
incompatibily issue when using load_dataset with datasets==3.0.1

### Describe the bug

There is a bug when using load_dataset with dataset version at 3.0.1 .
Please see below in the "steps to reproduce the bug".
To resolve the bug, I had to downgrade to version 2.21.0
OS: Ubuntu 24 (AWS instance)
Python: same bug under 3.12 and 3.10


The error I had was:
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/ubuntu/miniconda3/envs/maxence_env/lib/python3.10/site-packages/datasets/load.py", line 2096, in load_dataset
    builder_instance.download_and_prepare(
  File "/home/ubuntu/miniconda3/envs/maxence_env/lib/python3.10/site-packages/datasets/builder.py", line 924, in download_and_prepare
    self._download_and_prepare(
  File "/home/ubuntu/miniconda3/envs/maxence_env/lib/python3.10/site-packages/datasets/builder.py", line 1647, in _download_and_prepare
    super()._download_and_prepare(
  File "/home/ubuntu/miniconda3/envs/maxence_env/lib/python3.10/site-packages/datasets/builder.py", line 977, in _download_and_prepare
    split_generators = self._split_generators(dl_manager, **split_generators_kwargs)
  File "/home/ubuntu/.cache/huggingface/modules/datasets_modules/datasets/mozilla-foundation--common_voice_6_0/cb17afd34f5799f97e8f48398748f83006335b702bd785f9880797838d541b81/common_voice_6_0.py", line 159, in _split_generators
    archive_path = dl_manager.download(self._get_bundle_url(self.config.name, bundle_url_template))
  File "/home/ubuntu/miniconda3/envs/maxence_env/lib/python3.10/site-packages/datasets/download/download_manager.py", line 150, in download
    download_config = self.download_config.copy()
  File "/home/ubuntu/miniconda3/envs/maxence_env/lib/python3.10/site-packages/datasets/download/download_config.py", line 73, in copy
    return self.__class__(**{k: copy.deepcopy(v) for k, v in self.__dict__.items()})
TypeError: DownloadConfig.__init__() got an unexpected keyword argument 'ignore_url_params'

### Steps to reproduce the bug

1. install dataset with ```pip install datasets --upgrade```
2. launch python; from datasets import loaad_dataset
3. run load_dataset("mozilla-foundation/common_voice_6_0")
4. exit python
5. uninstall datasets; then ```pip install datasets==2.21.0```
6. launch python; from datasets import loaad_dataset
7. run load_dataset("mozilla-foundation/common_voice_6_0")
8. Everything runs great now

### Expected behavior

Be able to download a dataset without error

### Environment info

Copy-and-paste the text below in your GitHub issue.

- `datasets` version: 3.0.1
- Platform: Linux-6.8.0-1017-aws-x86_64-with-glibc2.39
- Python version: 3.12.4
- `huggingface_hub` version: 0.26.0
- PyArrow version: 17.0.0
- Pandas version: 2.2.3
- `fsspec` version: 2024.6.1
ds.map(f, num_proc=10) is slower than df.apply

### Describe the bug

pandas columns: song_id, song_name
ds = Dataset.from_pandas(df)

def has_cover(song_name):
    if song_name is None or pd.isna(song_name):
        return False
    return 'cover' in song_name.lower()

df['has_cover'] = df.song_name.progress_apply(has_cover)
ds = ds.map(lambda x: {'has_cover': has_cover(x['song_name'])}, num_proc=10)

time cost: 
1. df.apply: 100%|██████████| 12500592/12500592 [00:13<00:00, 959825.47it/s]
2. ds.map: Map (num_proc=10):  31%
 3899028/12500592 [00:28<00:38, 222532.89 examples/s]

### Steps to reproduce the bug

pandas columns: song_id, song_name
ds = Dataset.from_pandas(df)

def has_cover(song_name):
    if song_name is None or pd.isna(song_name):
        return False
    return 'cover' in song_name.lower()

df['has_cover'] = df.song_name.progress_apply(has_cover)
ds = ds.map(lambda x: {'has_cover': has_cover(x['song_name'])}, num_proc=10)

### Expected behavior

ds.map is ~num_proc faster than df.apply

### Environment info

pandas: 2.2.2
datasets: 2.19.1

Hi ! `map()` reads all the columns and writes the resulting dataset with all the columns as well, while df.column_name.apply only reads and writes one column and does it in memory. So this is speed difference is actually expected.

Moreover using multiprocessing on a dataset that lives in memory (from_pandas uses the same in-memory data as the pandas DataFrame while load_dataset or from_generator load from disk) requires to copy the data to each subprocess which can also be slow. Data loaded from disk don't need to be copied though since they work as a form of shared memory thanks to memory mapping.

However you can make you map() call much faster by making it read and write only the column you want:

```python
has_cover_ds = ds.map(lambda song_name: {'has_cover': has_cover(song_name)}, input_columns=["song_name"], remove_columns=ds.column_names)  # outputs a dataset with 1 column
ds = ds.concatenate_datasets([ds, has_cover_ds], axis=1)
```

and if your dataset is loaded from disk you can pass num_proc=10 and get a nice speed up as well (no need to copy the data to subprocesses)
Add repeat method to datasets

Following up on discussion in #6623 and #7198 I thought this would be pretty useful for my case so had a go at implementing.

My main motivation is to be able to call iterable_dataset.repeat(None).take(samples_per_epoch) to safely avoid timeout issues in a distributed training setting. This would provide a straightforward workaround for several open issues related to this situation:  https://github.com/huggingface/datasets/issues/6437, https://github.com/huggingface/datasets/issues/6594, https://github.com/huggingface/datasets/issues/6623, https://github.com/huggingface/datasets/issues/6719.

@lhoestq let me know if this looks on the right track!
concatenate_datasets does not preserve shuffling state

### Describe the bug

After concatenate datasets on an iterable dataset, the shuffling state is destroyed, similar to #7156 

This means concatenation cant be used for resolving uneven numbers of samples across devices when using iterable datasets in a distributed setting as discussed in #6623 

I also noticed that the number of shards is the same after concatenation, which I found surprising, but I don't understand the internals well enough to know whether this is actually surprising or not

### Steps to reproduce the bug

```python
import datasets
import torch.utils.data


def gen(shards):
    yield {"shards": shards}


def main():
    dataset1 = datasets.IterableDataset.from_generator(
        gen, gen_kwargs={"shards": list(range(25))}  # TODO: how to understand this?
    )
    dataset2 = datasets.IterableDataset.from_generator(
        gen, gen_kwargs={"shards": list(range(25, 50))}  # TODO: how to understand this?
    )
    dataset1 = dataset1.shuffle(buffer_size=1)
    dataset2 = dataset2.shuffle(buffer_size=1)
    print(dataset1.n_shards)
    print(dataset2.n_shards)

    dataset = datasets.concatenate_datasets(
        [dataset1, dataset2]
    )
    print(dataset.n_shards)
    # dataset = dataset1

    dataloader = torch.utils.data.DataLoader(
        dataset,
        batch_size=8,
        num_workers=0,
    )

    for i, batch in enumerate(dataloader):
        print(batch)
    print("\nNew epoch")

    dataset = dataset.set_epoch(1)

    for i, batch in enumerate(dataloader):
        print(batch)


if __name__ == "__main__":
    main()
```

### Expected behavior

Shuffling state should be preserved

### Environment info

Latest datasets
Add repeat() for iterable datasets

### Feature request

It would be useful to be able to straightforwardly repeat iterable datasets indefinitely, to provide complete control over starting and ending of iteration to the user.

An IterableDataset.repeat(n) function could do this automatically

### Motivation

This feature was discussed in this issue https://github.com/huggingface/datasets/issues/7147, and would resolve the need to use the hack of interleave datasets with probability 0 as a simple way to achieve this functionality.

An additional benefit might be the simplification of the use of iterable datasets in a distributed setting:
If the user can assume that datasets will repeat indefinitely, then issues around different numbers of samples appearing on different devices (e.g. https://github.com/huggingface/datasets/issues/6437, https://github.com/huggingface/datasets/issues/6594, https://github.com/huggingface/datasets/issues/6623, https://github.com/huggingface/datasets/issues/6719) can potentially be straightforwardly resolved by simply doing:

ids.repeat(None).take(n_samples_per_epoch)


### Your contribution

I'm not familiar enough with the codebase to assess how straightforward this would be to implement.

If it might be very straightforward, I could possibly have a go.

perhaps concatenate_datasets can already be used to achieve almost the same effect? 

`concatenate_datasets` does the job when there is a finite number of repetitions, but in case of `.repeat()` forever we need a new logic in `iterable_dataset.py`
[FSTimeoutError] load_dataset

### Describe the bug

When using `load_dataset`to load [HuggingFaceM4/VQAv2](https://huggingface.co/datasets/HuggingFaceM4/VQAv2), I am getting `FSTimeoutError`. 

### Error

```
TimeoutError: 

The above exception was the direct cause of the following exception:

FSTimeoutError                            Traceback (most recent call last)
[/usr/local/lib/python3.10/dist-packages/fsspec/asyn.py](https://klh9mr78js-496ff2e9c6d22116-0-colab.googleusercontent.com/outputframe.html?vrz=colab_20240924-060116_RC00_678132060#) in sync(loop, func, timeout, *args, **kwargs)
     99     if isinstance(return_result, asyncio.TimeoutError):
    100         # suppress asyncio.TimeoutError, raise FSTimeoutError
--> 101         raise FSTimeoutError from return_result
    102     elif isinstance(return_result, BaseException):
    103         raise return_result

FSTimeoutError:
```

It usually fails around 5-6 GB.

<img width="847" alt="Screenshot 2024-09-26 at 9 10 19 PM" src="https://github.com/user-attachments/assets/ff91995a-fb55-4de6-8214-94025d6c8470">


### Steps to reproduce the bug

To reproduce it, run this in colab notebook:

```
!pip install -q -U datasets

from datasets import load_dataset
ds = load_dataset('HuggingFaceM4/VQAv2', split="train[:10%]")
```



### Expected behavior

It should download properly.

### Environment info

Using Colab Notebook.

Is this `FSTimeoutError` due to download network issue from remote resource (from where it is being accessed)?

It seems to happen for all datasets, not just a specific one, and especially for versions after 3.0. (3.0.0, 3.0.1 have this problem)

I had the same error on a different dataset, but after downgrading to datasets==2.21.0, the problem was solved.

Same as https://github.com/huggingface/datasets/issues/7164

This dataset is made of a python script that downloads data from elsewhere than HF, so availability depends on the original host. Ultimately it would be nice to host the files of this dataset on HF

in `datasets` <3.0 there were lots of mechanisms that got removed after the decision to make datasets with python loading scripts legacy for security and maintenance reasons (we only do very basic support now)

@lhoestq Thank you for the clarification! Closing the issue.

I'm getting this too, and also at 5 minutes.  But for `CSTR-Edinburgh/vctk`, so it's not just this dataset, it seems to be a timeout that was introduced and needs to be raised.  The progress bar was moving along just fine before the timeout, and I get more or less of it depending on how fast the network is.

You can change the `aiohttp` timeout from 5min to 1h like this:

```python
import datasets, aiohttp
dataset = datasets.load_dataset(
    dataset_name,
    storage_options={'client_kwargs': {'timeout': aiohttp.ClientTimeout(total=3600)}}
)
```
interleave_datasets resets shuffle state

### Describe the bug

```
import datasets
import torch.utils.data


def gen(shards):
    yield {"shards": shards}


def main():
    dataset = datasets.IterableDataset.from_generator(
        gen,
        gen_kwargs={'shards': list(range(25))}
    )
    dataset = dataset.shuffle(buffer_size=1)
    dataset = datasets.interleave_datasets(
        [dataset, dataset], probabilities=[1, 0], stopping_strategy="all_exhausted"
    )

    dataloader = torch.utils.data.DataLoader(
        dataset,
        batch_size=8,
        num_workers=8,
    )

    for i, batch in enumerate(dataloader):
        print(batch)
        if i >= 10:
            break


if __name__ == "__main__":
     main()
```

### Steps to reproduce the bug

Run the script, it will output

```
{'shards': [tensor([ 0,  8, 16, 24,  0,  8, 16, 24])]}
{'shards': [tensor([ 1,  9, 17,  1,  9, 17,  1,  9])]}
{'shards': [tensor([ 2, 10, 18,  2, 10, 18,  2, 10])]}
{'shards': [tensor([ 3, 11, 19,  3, 11, 19,  3, 11])]}
{'shards': [tensor([ 4, 12, 20,  4, 12, 20,  4, 12])]}
{'shards': [tensor([ 5, 13, 21,  5, 13, 21,  5, 13])]}
{'shards': [tensor([ 6, 14, 22,  6, 14, 22,  6, 14])]}
{'shards': [tensor([ 7, 15, 23,  7, 15, 23,  7, 15])]}
{'shards': [tensor([ 0,  8, 16, 24,  0,  8, 16, 24])]}
{'shards': [tensor([17,  1,  9, 17,  1,  9, 17,  1])]}
{'shards': [tensor([18,  2, 10, 18,  2, 10, 18,  2])]}
```

### Expected behavior

The shards should be shuffled.

### Environment info

- `datasets` version: 3.0.0
- Platform: Linux-5.15.153.1-microsoft-standard-WSL2-x86_64-with-glibc2.35
- Python version: 3.10.12
- `huggingface_hub` version: 0.25.0
- PyArrow version: 17.0.0
- Pandas version: 2.0.3
- `fsspec` version: 2023.6.0
Datasets Unknown Keyword Argument Error - task_templates

### Describe the bug

Issue

```python
from datasets import load_dataset
examples = load_dataset('facebook/winoground', use_auth_token=<YOUR USER ACCESS TOKEN>)
```

Gives error

```
TypeError: DatasetInfo.__init__() got an unexpected keyword argument 'task_templates'
```

A simple downgrade to lower `datasets v 2.21.0` solves it.




### Steps to reproduce the bug

1. `pip install datsets`
2.
```python
from datasets import load_dataset
examples = load_dataset('facebook/winoground', use_auth_token=<YOUR USER ACCESS TOKEN>)
```



### Expected behavior

Should load the dataset correctly.

### Environment info

- Datasets version  `3.0.0`
- `transformers` version: 4.45.0.dev0
- Platform: Linux-6.8.0-40-generic-x86_64-with-glibc2.35
- Python version: 3.12.4
- Huggingface_hub version: 0.24.6
- Safetensors version: 0.4.5
- Accelerate version: 0.35.0.dev0
- Accelerate config:    not found
- PyTorch version (GPU?): 2.4.1+cu121 (True)
- Tensorflow version (GPU?): not installed (NA)
- Flax version (CPU?/GPU?/TPU?): not installed (NA)
- Jax version: not installed
- JaxLib version: not installed
- Using GPU in script?: Yes


Thanks, for reporting.

We have been fixing most Hub datasets to remove the deprecated (and now non-supported) task templates, but we missed the "facebook/winoground".

It is fixed now: https://huggingface.co/datasets/facebook/winoground/discussions/8