jamesLeeeeeee/datasets-github-issues huggingface dataset:
Start removing canonical datasets logic
Author: lhoestq | Pull request: yes | State: closed

I updated the source code and the documentation to start removing the "canonical datasets" logic.

Indeed this makes the documentation confusing and we don't want this distinction anymore in the future. Ideally users should share their datasets on the Hub directly.

### Changes

- the documentation about dataset loading mentions the datasets on the Hub (no difference between canonical and community, since they all have their own repository now)
- the documentation about adding a dataset doesn't explain the technical differences between canonical and community anymore, and only presents how to add a community dataset. There is still a small section at the bottom that mentions the datasets that are still on GitHub and redirects to the `ADD_NEW_DATASET.md` guide on GitHub about how to contribute a dataset to the `datasets` library
- the code source doesn't mention "canonical" anymore anywhere. There is still a `GitHubDatasetModuleFactory` class that is left, but I updated the docstring to say that it will be eventually removed in favor of the `HubDatasetModuleFactory` classes that already exist

Would love to have your feedbacks on this !

cc @julien-c @thomwolf @SBrandeis
Allow download only some files from the Wikipedia dataset
Author: jvanz | Pull request: no | State: open

**Is your feature request related to a problem? Please describe.**
The Wikipedia dataset can be really big. This is a problem if you want to use it locally in a laptop with the Apache Beam `DirectRunner`. Even if your laptop have a considerable amount of memory (e.g. 32gb).


**Describe the solution you'd like**
I would like to use the `data_files` argument in the `load_dataset` function to define which file in the wikipedia dataset I would like to download. Thus, I can work with the dataset in a smaller machine using the Apache Beam `DirectRunner`.

**Describe alternatives you've considered**
I've tried to use the `simple` Wikipedia dataset. But it's in English and I would like to use Portuguese texts in my model.
Checksum mismatch for the reddit_tifu dataset
Author: anna-kay | Pull request: no | State: closed

## Describe the bug
A checksum occurs when downloading the reddit_tifu data (both long & short).

## Steps to reproduce the bug
reddit_tifu_dataset = load_dataset('reddit_tifu', 'long')

## Expected results
The expected result is for the dataset to be downloaded and cached locally.

## Actual results
  File "/.../lib/python3.9/site-packages/datasets/utils/info_utils.py", line 40, in verify_checksums
    raise NonMatchingChecksumError(error_msg + str(bad_urls))
datasets.utils.info_utils.NonMatchingChecksumError: Checksums didn't match for dataset source files:
['https://drive.google.com/uc?export=download&id=1ffWfITKFMJeqjT8loC8aiCLRNJpc_XnF']

## Environment info
<!-- You can run the command `datasets-cli env` and copy-and-paste its output below. -->
- `datasets` version: 1.18.3
- Platform: Linux-5.13.0-30-generic-x86_64-with-glibc2.31
- Python version: 3.9.7
- PyArrow version: 7.0.0
DuplicatedKeysError on msr_sqa dataset
Author: kolk | Pull request: no | State: closed

### Describe the bug
Failure to generate dataset msr_sqa because of duplicate keys.

### Steps to reproduce the bug
```
from datasets import load_dataset
load_dataset("msr_sqa")
```
### Expected results
The examples keys should be unique.

**Actual results**
```
>>> load_dataset("msr_sqa")
Downloading:
6.72k/? [00:00<00:00, 148kB/s]
Downloading:
2.93k/? [00:00<00:00, 53.8kB/s]
Using custom data configuration default
Downloading and preparing dataset msr_sqa/default (download: 4.57 MiB, generated: 26.25 MiB, post-processed: Unknown size, total: 30.83 MiB) to /root/.cache/huggingface/datasets/msr_sqa/default/0.0.0/70b2a497bd3cc8fc960a3557d2bad1eac5edde824505e15c9c8ebe4c260fd4d1...
Downloading: 100%
4.80M/4.80M [00:00<00:00, 7.49MB/s]
---------------------------------------------------------------------------
DuplicatedKeysError                       Traceback (most recent call last)
[/usr/local/lib/python3.7/dist-packages/datasets/builder.py](https://localhost:8080/#) in _prepare_split(self, split_generator)
   1080                     example = self.info.features.encode_example(record)
-> 1081                     writer.write(example, key)
   1082             finally:

8 frames
DuplicatedKeysError: FAILURE TO GENERATE DATASET !
Found duplicate Key: nt-639
Keys should be unique and deterministic in nature

During handling of the above exception, another exception occurred:

DuplicatedKeysError                       Traceback (most recent call last)
[/usr/local/lib/python3.7/dist-packages/datasets/arrow_writer.py](https://localhost:8080/#) in check_duplicate_keys(self)
    449         for hash, key in self.hkey_record:
    450             if hash in tmp_record:
--> 451                 raise DuplicatedKeysError(key)
    452             else:
    453                 tmp_record.add(hash)

DuplicatedKeysError: FAILURE TO GENERATE DATASET !
Found duplicate Key: nt-639
Keys should be unique and deterministic in nature
```

### Environment info
datasets version: 1.18.3
Platform: Google colab notebook
Python version: 3.7
PyArrow version: 6.0.1
`dataset = dataset.map()` causes faiss index lost
Author: Oaklight | Pull request: no | State: open

## Describe the bug
assigning the resulted dataset to original dataset causes lost of the faiss index

## Steps to reproduce the bug
`my_dataset` is a regular loaded dataset. It's a part of a customed dataset structure
```python
self.dataset.add_faiss_index('embeddings')
self.dataset.list_indexes()
# ['embeddings']

dataset2 = my_dataset.map(
    lambda x: self._get_nearest_examples_batch(x['text']), batch=True
)

# the unexpected result:
dataset2.list_indexes()
# []

self.dataset.list_indexes()
# ['embeddings']
```

in case something wrong with my `_get_nearest_examples_batch()`, it's like this
```python
def _get_nearest_examples_batch(self, examples, k=5):
    queries = embed(examples)
    scores_batch, retrievals_batch = self.dataset.get_nearest_examples_batch(self.faiss_column, queries, k)
    return {
        'neighbors': [batch['text'] for batch in retrievals_batch],
        'scores': scores_batch
    }
```

## Expected results
`map` shouldn't drop the indexes, in another word, indexes should be carried to the generated dataset

## Actual results
map drops the indexes

## Environment info
<!-- You can run the command `datasets-cli env` and copy-and-paste its output below. -->
- `datasets` version: 1.18.3
- Platform: Ubuntu 20.04.3 LTS
- Python version: 3.8.12
- PyArrow version: 7.0.0
`Dataset.class_encode` should support custom class names
Author: Dref360 | Pull request: no | State: closed

I can make a PR, just wanted approval before starting.

**Is your feature request related to a problem? Please describe.**

It is often the case that classes are not ordered in alphabetical order. Current `class_encode_column` sort the classes before indexing.
https://github.com/huggingface/datasets/blob/master/src/datasets/arrow_dataset.py#L1235

**Describe the solution you'd like**
I would like to add a **optional** parameter `class_names` to `class_encode_column` that would  be used for the mapping instead of sorting the unique values.

**Describe alternatives you've considered**

One can use map instead. I find it harder to read.
```python
CLASS_NAMES = ['apple', 'orange', 'potato']
ds = ds.map(lambda item: CLASS_NAMES.index(item[label_column]))

# Proposition
ds = ds.class_encode_column(label_column, CLASS_NAMES)
```

**Additional context**

I can make the PR if this feature is accepted.
Unable to view the Gradio flagged call back dataset
Author: kingabzpro | Pull request: no | State: closed

## Dataset viewer issue for '*savtadepth-flags*'

**Link:** *[savtadepth-flags](https://huggingface.co/datasets/kingabzpro/savtadepth-flags)*

*with the Gradio 2.8.1 the dataset viers stopped working. I tried to add values manually but its not working. The dataset is also not showing the link with the app https://huggingface.co/spaces/kingabzpro/savtadepth.*

Am I the one who added this dataset ? Yes
head_qa file missing
Author: severo | Pull request: no | State: closed

## Describe the bug

A file for the `head_qa` dataset is missing (https://drive.google.com/u/0/uc?export=download&id=1a_95N5zQQoUCq8IBNVZgziHbeM-QxG2t/HEAD_EN/train_HEAD_EN.json)

## Steps to reproduce the bug
```python
>>> from datasets import load_dataset
>>> load_dataset("head_qa", name="en")
```

## Expected results

The dataset should be loaded

## Actual results

```
Downloading and preparing dataset head_qa/en (download: 75.69 MiB, generated: 2.69 MiB, post-processed: Unknown size, total: 78.38 MiB) to /home/slesage/.cache/huggingface/datasets/head_qa/en/1.1.0/583ab408e8baf54aab378c93715fadc4d8aa51b393e27c3484a877e2ac0278e9...
Downloading data: 2.21kB [00:00, 2.05MB/s]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/slesage/hf/datasets-preview-backend/.venv/lib/python3.9/site-packages/datasets/load.py", line 1729, in load_dataset
    builder_instance.download_and_prepare(
  File "/home/slesage/hf/datasets-preview-backend/.venv/lib/python3.9/site-packages/datasets/builder.py", line 594, in download_and_prepare
    self._download_and_prepare(
  File "/home/slesage/hf/datasets-preview-backend/.venv/lib/python3.9/site-packages/datasets/builder.py", line 665, in _download_and_prepare
    verify_checksums(
  File "/home/slesage/hf/datasets-preview-backend/.venv/lib/python3.9/site-packages/datasets/utils/info_utils.py", line 40, in verify_checksums
    raise NonMatchingChecksumError(error_msg + str(bad_urls))
datasets.utils.info_utils.NonMatchingChecksumError: Checksums didn't match for dataset source files:
['https://drive.google.com/u/0/uc?export=download&id=1a_95N5zQQoUCq8IBNVZgziHbeM-QxG2t']
```

## Environment info
- `datasets` version: 1.18.4.dev0
- Platform: Linux-5.11.0-1028-aws-x86_64-with-glibc2.31
- Python version: 3.9.6
- PyArrow version: 6.0.1
Add perplexity to metrics
Author: emibaylor | Pull request: yes | State: closed

Adding perplexity metric

This code differs from the code in [this](https://huggingface.co/docs/transformers/perplexity) HF blog post because the blogpost code fails in at least the following circumstances:
- returns nans whenever the stride = 1
- hits a runtime error when the stride is significantly larger than the max model length (e.g. if max_model_length = 512 and stride = 1024)


Note that:
- As it is, it only works for causal models. Pseudoperplexity can be added later as another metric to work with masked language models.
- It takes in a list of strings so that it can be dataset independent. This does mean that it doesn't currently batch inputs, and is therefore relatively slow.
- It overwrites the metrics compute() function for a specific perplexity compute() function. This is because the current general metrics compute() function requires model-generated predictions, which doesn't make sense in the context of perplexity
Images get decoded when using `map()` with `input_columns` argument on a dataset
Author: kklemon | Pull request: no | State: closed

## Describe the bug

The `datasets.features.Image` feature class decodes image data by default. Expectedly, when indexing a dataset or using the `map()` method, images are returned as PIL Image instances.

However, when calling `map()` and setting a specific data column with the `input_columns` argument, the image data is passed as raw byte representation to the mapping function.

## Steps to reproduce the bug
```python
from datasets import load_dataset
from torchvision import transforms
from PIL.Image import Image

dataset = load_dataset('mnist', split='train')

def transform_all_columns(example):
    # example['image'] is encoded as PIL Image
    assert isinstance(example['image'], Image)
    return example

def transform_image_column(image):
    # image is decoded here and represented as raw bytes
    assert isinstance(image, Image)
    return image

# single-sample dataset for debugging purposes
dev = dataset.select([0])

dev.map(transform_all_columns)
dev.map(transform_image_column, input_columns='image')
```

## Expected results

Image data should be passed in decoded form, i.e. as PIL Image objects to the mapping function unless the `decode` attribute on the image feature is set to `False`.

## Actual results

The mapping function receives images as raw byte data.

## Environment info
- `datasets` version: 1.18.3
- Platform: Linux-5.11.0-49-generic-x86_64-with-glibc2.32
- Python version: 3.8.0b4
- PyArrow version: 7.0.0
Cannot preview dataset
Author: frascuchon | Pull request: no | State: closed

## Dataset viewer issue for '*rubrix/news*'

**Link:https://huggingface.co/datasets/rubrix/news** *link to the dataset viewer page*

Cannot see the dataset preview:

```
Status code:   400
Exception:     Status400Error
Message:       Not found. Cache is waiting to be refreshed.
```
Am I the one who added this dataset ? No
Overflowing indices in `select`
Author: lvwerra | Pull request: no | State: closed

## Describe the bug
The `Dataset.select` function seems to accept indices that are larger than the dataset size and seems to effectively use `index %len(ds)`.

## Steps to reproduce the bug
```python
from datasets import Dataset

ds = Dataset.from_dict({"test": [1,2,3]})
ds = ds.select(range(5))

print(ds)
print()
print(ds["test"])
```
Result:
```python
Dataset({
    features: ['test'],
    num_rows: 5
})

[1, 2, 3, 1, 2]
```

This behaviour is not documented and can lead to unexpected behaviour when for example taking a sample larger than the dataset and thus creating a lot of duplicates.

## Expected results
It think this should throw an error or at least a very big warning:
```python
IndexError: Invalid key: 5 is out of bounds for size 3
```

## Environment info
- `datasets` version: 1.18.3
- Platform: macOS-12.0.1-x86_64-i386-64bit
- Python version: 3.9.10
- PyArrow version: 7.0.0
Expanding streaming capabilities
Author: lvwerra | Pull request: no | State: open

Some ideas for a few features that could be useful when working with large datasets in streaming mode. 

## `filter` for `IterableDataset`
Adding filtering to streaming datasets would be useful in several scenarios:
- filter a dataset with many languages for a subset of languages
- filter a dataset for specific licenses
- other custom logic to get a subset
The only way to achieve this at the moment is I think through writing a custom loading script and implementing filters there.

## `IterableDataset` to `Dataset` conversion
In combination with the above filter a functionality to "play" the whole stream would be useful. The motivation is that often one might filter the dataset to get a manageable size for experimentation. In that case streaming mode is no longer necessary as the filtered dataset is small enough and it would be useful to be able to play through the whole stream to create a normal `Dataset` with all its benefits.

```python
ds = load_dataset("some_large_dataset", streaming=True) 
ds_filter = ds.filter(lambda x: x["lang"]="fr")
ds_filter = ds_filter.stream() # here the `IterableDataset` is converted to a `Dataset`
```
Naturally, this could be expanded with `stream(n=1000)` which creates a `Dataset` with the first `n` elements similar to `take`.

## Stream to the Hub
While streaming allows to use a dataset as is without saving the whole dataset on the local machine it is currently not possible to process a dataset and add it to the hub. The only way to do this is by downloading the full dataset and saving the processed dataset again before pushing them to the hub. The API could looks something like:

```python
ds = load_dataset("some_large_dataset", streaming=True)
ds_filter = ds.filter(some_filter_func)
ds_processed = ds_filter.map(some_processing_func)
ds_processed.push_to_hub("new_better_dataset", batch_size=100_000)
```

Under the hood this could be done by processing and aggregating `batch_size` elements and then pushing that batch as a single file to the hub. With this functionality one could process and create TB scale datasets while only requiring size of `batch_size` local disk space.

cc @lhoestq @albertvillanova
`NonMatchingSplitsSizesError` for cats_vs_dogs dataset
Author: jaketae | Pull request: no | State: closed

## Describe the bug

Cannot download cats_vs_dogs dataset due to `NonMatchingSplitsSizesError`.

## Steps to reproduce the bug
```python
from datasets import load_dataset
dataset = load_dataset("cats_vs_dogs")
```

## Expected results

Loading is successful.

## Actual results

```
NonMatchingSplitsSizesError: [{'expected': SplitInfo(name='train', num_bytes=7503250, num_examples=23422, dataset_name='cats_vs_dogs'), 'recorded': SplitInfo(name='train', num_bytes=7262410, num_examples=23410, dataset_name='cats_vs_dogs')}]
```

## Environment info

Reproduced on a fresh [Colab notebook](https://colab.research.google.com/drive/13GTvrSJbBGvL2ybDdXCBZwATd6FOkMub?usp=sharing).

## Additional Context

Originally reported in https://github.com/huggingface/transformers/issues/15698.

cc @mariosasko
Passing invalid subset should throw an error
Author: jxmorris12 | Pull request: no | State: open

## Describe the bug
Only some datasets have a subset (as in `load_dataset(name, subset)`). If you pass an invalid subset, an error should be thrown.

## Steps to reproduce the bug
```python
import datasets
datasets.load_dataset('rotten_tomatoes', 'asdfasdfa')
```

## Expected results
This should break, since `'asdfasdfa'` isn't a subset of the `rotten_tomatoes` dataset.

## Actual results
This API call silently succeeds.
Use the same seed to shuffle shards and metadata in streaming mode
Author: lhoestq | Pull request: yes | State: closed

When shuffling in streaming mode, those two entangled lists are shuffled independently. In this PR I changed this to shuffle the lists of same length with the exact same seed, in order for the files and metadata to still be aligned.
```python
gen_kwargs = {
    "files": [os.path.join(data_dir, filename) for filename in all_files],
    "metadata_files": [all_metadata[filename] for filename in all_files],
}
```
IMO this is important to avoid big but silent issues.

Fix https://github.com/huggingface/datasets/issues/3744
Add mIoU metric
Author: NielsRogge | Pull request: yes | State: closed

This PR adds the mean Intersection-over-Union metric to the library, useful for tasks like semantic segmentation.

It is entirely based on mmseg's [implementation](https://github.com/open-mmlab/mmsegmentation/blob/master/mmseg/core/evaluation/metrics.py).

I've removed any PyTorch dependency, and rely on Numpy only.
Better shards shuffling in streaming mode
Author: lhoestq | Pull request: no | State: closed

Sometimes a dataset script has a `_split_generators` that returns several files as well as the corresponding metadata of each file. It often happens that they end up in two separate lists in the `gen_kwargs`:
```python
gen_kwargs = {
    "files": [os.path.join(data_dir, filename) for filename in all_files],
    "metadata_files": [all_metadata[filename] for filename in all_files],
}
```
It happened for Multilingual Spoken Words for example in #3666

However currently **the two lists are shuffled independently** when shuffling the shards in streaming mode. This leads to `_generate_examples` not having the right metadata for each file.

To prevent this issue I suggest that we always shuffle lists of the same length the exact same way to avoid such a big but silent issue.

cc @polinaeterna
Fix ValueError message formatting in int2str
Author: akulchik | Pull request: yes | State: closed

Hi!

I bumped into this particular `ValueError` during my work (because an instance of `np.int64` was passed instead of regular Python `int`), and so I had to `print(type(values))` myself. Apparently, it's just the missing `f` to make message an f-string.

It ain't much for a contribution, but it's honest work. Hope it spares someone else a few seconds in the future 😃
Support streaming for pubmed
Author: abhi-mosaic | Pull request: yes | State: closed

This PR makes some minor changes to the `pubmed` dataset to allow for `streaming=True`. Fixes #3739.

Basically, I followed the C4 dataset which works in streaming mode as an example, and made the following changes:

* Change URL prefix from `ftp://` to `https://`
* Explicilty `open` the filename and pass the XML contents to `etree.fromstring(xml_str)`

The Github diff tool makes it look like the changes are larger than they are, sorry about that.

I tested locally and the `pubmed` dataset now works in both normal and streaming modes. There is some overhead at the start of each shard in streaming mode as building the XML tree online is quite slow (each pubmed .xml.gz file is ~20MB), but the overhead gets amortized over all the samples in the shard. On my laptop with a single CPU worker I am able to stream at about ~600 samples/s.
Pubmed dataset does not work in streaming mode
Author: abhi-mosaic | Pull request: no | State: closed

## Describe the bug
Trying to use the `pubmed` dataset with `streaming=True` fails.

## Steps to reproduce the bug
```python
import datasets
pubmed_train = datasets.load_dataset('pubmed', split='train', streaming=True)
print (next(iter(pubmed_train)))
```

## Expected results
I would expect to see the first training sample from the pubmed dataset. 

## Actual results
```
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/abhinav/Documents/mosaicml/mosaicml_venv/lib/python3.8/site-packages/datasets/iterable_dataset.py", line 367, in __iter__
    for key, example in self._iter():
  File "/Users/abhinav/Documents/mosaicml/mosaicml_venv/lib/python3.8/site-packages/datasets/iterable_dataset.py", line 364, in _iter
    yield from ex_iterable
  File "/Users/abhinav/Documents/mosaicml/mosaicml_venv/lib/python3.8/site-packages/datasets/iterable_dataset.py", line 79, in __iter__
    for key, example in self.generate_examples_fn(**self.kwargs):
  File "/Users/abhinav/.cache/huggingface/modules/datasets_modules/datasets/pubmed/9715addf10c42a7877a2149ae0c5f2fddabefc775cd1bd9b03ac3f012b86ce46/pubmed.py", line 373, in _generate_examples
    tree = etree.parse(filename)
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/lib/python3.8/xml/etree/ElementTree.py", line 1202, in parse
    tree.parse(source, parser)
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/lib/python3.8/xml/etree/ElementTree.py", line 584, in parse
    source = open(source, "rb")
FileNotFoundError: [Errno 2] No such file or directory: 'gzip://pubmed21n0001.xml::ftp://ftp.ncbi.nlm.nih.gov/pubmed/baseline/pubmed21n0001.xml.gz'
```
## Environment info
<!-- You can run the command `datasets-cli env` and copy-and-paste its output below. -->
- `datasets` version: 1.18.2
- Platform: macOS-11.4-x86_64-i386-64bit
- Python version: 3.8.2
- PyArrow version: 6.0.0

## Comments
The error looks like an issue with `open` vs. `xopen` inside the `xml` package. It looks like it's trying to open the remote source URL, which has been edited with prefix `gzip://...`. 

Maybe there can be an explicit `xopen` before passing the raw data to `etree`, something like:

```python
# Before
tree = etree.parse(filename)
root = tree.getroot()

# After
with xopen(filename) as f:
  data_str = f.read()
root = etree.fromstring(data_str)
```