Add Dataset.from_spark

Adds static method Dataset.from_spark to create datasets from Spark DataFrames.

This approach alleviates users of the need to materialize their dataframe---a common use case is that the user loads their dataset into a dataframe, uses Spark to apply some transformation to some of the columns, and then wants to train on the dataset.

Related issue: https://github.com/huggingface/datasets/issues/5678


_The documentation is not available anymore as the PR was closed or merged._

@mariosasko Would you or another HF datasets maintainer be able to review this, please?

Amazing ! Great job @maddiedawson 

Do you know if it's possible to also support writing to Parquet using the HF ParquetWriter if `file_format="parquet"` ?

Parquet is often used when people want to stream the data to train models - which is suitable for big datasets. On the other hand Arrow is generally used for local memory mapping with random access.

> Please note there was a previous PR adding this functionality

Am I right to say that it uses the spark workers to prepare the Arrow files ? If so this should make the data preparation fast and won't fill up the executor's memory as in the previously proposed PR

Thanks for taking a look! Unlike the previous PR's approach, this implementation takes advantage of Spark mapping to distribute file writing over multiple tasks. (Also it doesn't load the entire dataset into memory :) )

Supporting Parquet here sgtm; I'll modify the PR.

I also updated the PR description with a common Spark-HF use case that we want to improve.

Hey @albertvillanova @lhoestq , would one of you be able to re-review please? Thank you!

@lhoestq this is ready for another pass! Thanks so much 🙏 

Friendly ping @lhoestq , also cc @polinaeterna who may be able to help take a look?

Merging `main` into this branch should fix the CI

Just rebased @lhoestq 

Thanks @lhoestq ! Is there a way for me to trigger the github workflow myself to triage the test failure? I'm not able to repro the test failures locally.

There were two test issues in the workflow that I wasn't able to reproduce locally:

- Python 3.7: createDataFrame fails due to a pickling error. I modified the tests to instead write and read from json files
- Python 3.10: A worker crashes for unknown reasons. I modified the spark setup to explicitly specify local mode in case it was trying to do something else; let's see if that fixes the issue

Also one more question @lhoestq when is the next datasets release? We're hoping this can make it in

I just re-ran the CI.
I think we can do a release right after this PR is merged ;)

Thanks all! @lhoestq could we re-run CI again please? I think we have to disable this feature on python 3.7 due to the pickling error. The other failure was due to https://issues.apache.org/jira/browse/SPARK-30952 so I rewrote the df processing

Thanks @lhoestq , this is ready for another CI run. I pinned the pyspark version to see if that fixes the pickling issue

The remaining CI issues have been addressed! They were

- dill=0.3.1.1 is incompatible with cloudpickle, used by Spark. The min-dependency tests use this dill version, and those were failing. I added a skip-test annotation to skip Spark tests when using this dill version. This shouldn't be a production issue since if users are using that version of dill, they won't really be able to do anything with Spark anyway.
- One of the Spark APIs used in this feature (mapInArrow) is incompatible with Windows. I filed a Spark ticket for the team to investigate. For the tests, I added another annotation to skip Spark tests on Windows. In the next PR (adding streaming mode), we should be able to support Windows since that won't use mapInArrow.

I ran the CI on my forked branch: https://github.com/maddiedawson/datasets/pull/2 Everything passes except one instance of tests/test_metric_common.py::LocalMetricTest::test_load_metric_frugalscore; it looks like a flake.

@lhoestq granted that the CI passes here, is this ok to merge and release? We'd like to put out a blog post tomorrow to broadcast this to Spark users!

Thanks @lhoestq ! Could you help take a look at the error please? Seems unrelated...

FAILED tests/test_arrow_dataset.py::BaseDatasetTest::test_map_multiprocessing_on_disk - NotADirectoryError: [WinError 267] The directory name is invalid: 'C:\\Users\\RUNNER~1\\AppData\\Local\\Temp\\tmptfnrdj4x\\cache-5c5687cf5629c97a_00000_of_00002.arrow'
===== 1 failed, 2152 passed, 23 skipped, 20 warnings in 461.68s (0:07:41) =====

The blog is live btw! https://www.databricks.com/blog/contributing-spark-loader-for-hugging-face-datasets Hopefully there can be a release today?

<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.012686 / 0.011353 (0.001333) | 0.006051 / 0.011008 (-0.004957) | 0.123057 / 0.038508 (0.084549) | 0.033238 / 0.023109 (0.010128) | 0.388207 / 0.275898 (0.112309) | 0.393972 / 0.323480 (0.070492) | 0.006645 / 0.007986 (-0.001340) | 0.006715 / 0.004328 (0.002386) | 0.098348 / 0.004250 (0.094097) | 0.041410 / 0.037052 (0.004358) | 0.380123 / 0.258489 (0.121634) | 0.427982 / 0.293841 (0.134141) | 0.052194 / 0.128546 (-0.076352) | 0.018775 / 0.075646 (-0.056871) | 0.399063 / 0.419271 (-0.020209) | 0.061019 / 0.043533 (0.017487) | 0.370943 / 0.255139 (0.115804) | 0.398326 / 0.283200 (0.115127) | 0.136893 / 0.141683 (-0.004790) | 1.777431 / 1.452155 (0.325276) | 1.844354 / 1.492716 (0.351638) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.267296 / 0.018006 (0.249289) | 0.565133 / 0.000490 (0.564643) | 0.005811 / 0.000200 (0.005611) | 0.000122 / 0.000054 (0.000068) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.027009 / 0.037411 (-0.010402) | 0.125907 / 0.014526 (0.111381) | 0.122111 / 0.176557 (-0.054445) | 0.189023 / 0.737135 (-0.548112) | 0.140510 / 0.296338 (-0.155829) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.589269 / 0.215209 (0.374060) | 6.038038 / 2.077655 (3.960384) | 2.394681 / 1.504120 (0.890561) | 2.099268 / 1.541195 (0.558073) | 2.105146 / 1.468490 (0.636656) | 1.216304 / 4.584777 (-3.368473) | 5.823110 / 3.745712 (2.077397) | 4.999323 / 5.269862 (-0.270539) | 2.781554 / 4.565676 (-1.784122) | 0.148370 / 0.424275 (-0.275905) | 0.015163 / 0.007607 (0.007556) | 0.775153 / 0.226044 (0.549109) | 7.425314 / 2.268929 (5.156385) | 3.320254 / 55.444624 (-52.124370) | 2.718595 / 6.876477 (-4.157881) | 2.696215 / 2.142072 (0.554142) | 1.452249 / 4.805227 (-3.352978) | 0.281355 / 6.500664 (-6.219309) | 0.088146 / 0.075469 (0.012677) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.495718 / 1.841788 (-0.346070) | 17.498714 / 8.074308 (9.424405) | 20.109705 / 10.191392 (9.918313) | 0.233053 / 0.680424 (-0.447371) | 0.028336 / 0.534201 (-0.505865) | 0.538146 / 0.579283 (-0.041137) | 0.642106 / 0.434364 (0.207742) | 0.597214 / 0.540337 (0.056876) | 0.732219 / 1.386936 (-0.654717) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008153 / 0.011353 (-0.003200) | 0.005605 / 0.011008 (-0.005403) | 0.096159 / 0.038508 (0.057651) | 0.034102 / 0.023109 (0.010992) | 0.428091 / 0.275898 (0.152193) | 0.476535 / 0.323480 (0.153056) | 0.006278 / 0.007986 (-0.001708) | 0.006752 / 0.004328 (0.002424) | 0.100553 / 0.004250 (0.096302) | 0.045546 / 0.037052 (0.008494) | 0.463236 / 0.258489 (0.204747) | 0.502512 / 0.293841 (0.208671) | 0.051014 / 0.128546 (-0.077533) | 0.018499 / 0.075646 (-0.057148) | 0.127587 / 0.419271 (-0.291685) | 0.059254 / 0.043533 (0.015722) | 0.432248 / 0.255139 (0.177109) | 0.462002 / 0.283200 (0.178802) | 0.124918 / 0.141683 (-0.016765) | 1.689740 / 1.452155 (0.237585) | 1.871546 / 1.492716 (0.378830) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.274844 / 0.018006 (0.256838) | 0.570522 / 0.000490 (0.570032) | 0.004008 / 0.000200 (0.003808) | 0.000146 / 0.000054 (0.000091) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.025323 / 0.037411 (-0.012088) | 0.116323 / 0.014526 (0.101797) | 0.129434 / 0.176557 (-0.047122) | 0.187069 / 0.737135 (-0.550067) | 0.134459 / 0.296338 (-0.161880) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.633551 / 0.215209 (0.418341) | 6.290078 / 2.077655 (4.212423) | 2.692071 / 1.504120 (1.187951) | 2.354344 / 1.541195 (0.813149) | 2.409260 / 1.468490 (0.940770) | 1.270515 / 4.584777 (-3.314261) | 5.552982 / 3.745712 (1.807270) | 3.041417 / 5.269862 (-2.228444) | 1.920634 / 4.565676 (-2.645043) | 0.142500 / 0.424275 (-0.281775) | 0.014378 / 0.007607 (0.006770) | 0.786444 / 0.226044 (0.560399) | 7.711558 / 2.268929 (5.442630) | 3.439688 / 55.444624 (-52.004936) | 2.742314 / 6.876477 (-4.134163) | 2.800531 / 2.142072 (0.658458) | 1.405843 / 4.805227 (-3.399385) | 0.245322 / 6.500664 (-6.255342) | 0.076662 / 0.075469 (0.001193) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.592961 / 1.841788 (-0.248827) | 18.165647 / 8.074308 (10.091339) | 20.011433 / 10.191392 (9.820041) | 0.240558 / 0.680424 (-0.439866) | 0.026045 / 0.534201 (-0.508156) | 0.529610 / 0.579283 (-0.049674) | 0.652494 / 0.434364 (0.218130) | 0.612284 / 0.540337 (0.071947) | 0.733180 / 1.386936 (-0.653756) |

</details>
</details>

![](https://cml.dev/watermark.png#ea251c726c73bd076a1bef7e39e2ac4e97c8d166 "CML watermark")


python 3.9.2
Got an error  _pickle.PicklingError use Dataset.from_spark.

Did the dataset import load data from spark dataframe using multi-node Spark cluster
df = spark.read.parquet(args.input_data).repartition(50)
ds = Dataset.from_spark(df, keep_in_memory=True,
                        cache_dir="/pnc-data/data/nuplan/t5_spark/cache_data")
ds.save_to_disk(args.output_data)

Error : 
_pickle.PicklingError: Could not serialize object: RuntimeError: It appears that you are attempting to reference SparkContext from a broadcast variable, action, or transforma
tion. SparkContext can only be used on the driver, not in code that it run on workers. For more information, see SPARK-5063.
23/06/16 21:17:20 WARN ExecutorPodsWatchSnapshotSource: Kubernetes client has been closed (this is expected if the application is shutting down.)


Hi @yanzia12138 ! Could you open a new issue please and share the full stack trace ? This will help to know what happened exactly