1.12.1

Bug fixes

• Fix fsspec AbstractFileSystem access #2915 (@pierre-godard)
• Fix unwanted tqdm bar when accessing examples #2920 (@lhoestq)
• Fix conversion of multidim arrays in list to arrow #2922 (@lhoestq):
  • this fixes the ArrowInvalid: Can only convert 1-dimensional array values errors

1.12.0

New documentation

• New documentation structure #2718 (@stevhliu):
  • New: Tutorials
  • New: Hot-to guides
  • New: Conceptual guides
  • Update: Reference

See the new documentation here !

Datasets changes

• New: VIVOS dataset for Vietnamese ASR #2780 (@binh234)
• New: The Pile books3 #2801 (@richarddwang)
• New: The Pile stack exchange #2803 (@richarddwang)
• New: The Pile openwebtext2 #2802 (@richarddwang)
• New: Food-101 #2804 (@nateraw)
• New: Beans #2809 (@nateraw)
• New: cedr #2796 (@naumov-al)
• New: cats_vs_dogs #2807 (@nateraw)
• New: MultiEURLEX #2865 (@iliaschalkidis)
• New: BIOSSES #2881 (@bwang482)
• Update: TTC4900 - add download URL #2732 (@yavuzKomecoglu)
• Update: Wikihow - Generate metadata JSON for wikihow dataset #2748 (@albertvillanova)
• Update: lm1b - Generate metadata JSON #2752 (@albertvillanova)
• Update: reclor - Generate metadata JSON #2753 (@albertvillanova)
• Update: telugu_books - Generate metadata JSON #2754 (@albertvillanova)
• Update: SUPERB - Add SD task #2661 (@albertvillanova)
• Update: SUPERB - Add KS task #2783 (@anton-l)
• Update: GooAQ - add train/val/test splits #2792 (@bhavitvyamalik)
• Update: Openwebtext - update size #2857 (@lhoestq)
• Update: timit_asr - make the dataset streamable #2835 (@lhoestq)
• Fix: journalists_questions -fix key by recreating metadata JSON #2744 (@albertvillanova)
• Fix: turkish_movie_sentiment - fix metadata JSON #2755 (@albertvillanova)
• Fix: ubuntu_dialogs_corpus - fix metadata JSON #2756 (@albertvillanova)
• Fix: CNN/DailyMail - typo #2791 (@omaralsayed)
• Fix: linnaeus - fix url #2852 (@lhoestq)
• Fix ToTTo - fix data URL #2864 (@albertvillanova)
• Fix: wikicorpus - fix keys #2844 (@lhoestq)
• Fix: COUNTER - fix bad file name #2894 (@albertvillanova)
• Fix: DocRED - fix data URLs and metadata #2883 (@albertvillanova)

Datasets features

• Load Dataset from the Hub (NO DATASET SCRIPT) #2662 (@lhoestq)
• Preserve dtype for numpy/torch/tf/jax arrays #2361 (@bhavitvyamalik)
• add multi-proc in to_json #2747 (@bhavitvyamalik)
• Optimize Dataset.filter to only compute the indices to keep #2836 (@lhoestq)

Dataset streaming - better support for compression:

• Fix streaming zip files #2798 (@albertvillanova)
• Support streaming tar files #2800 (@albertvillanova)
• Support streaming compressed files (gzip, bz2, lz4, xz, zst) #2786 (@albertvillanova)
• Fix streaming zip files from canonical datasets #2805 (@albertvillanova)
• Add url prefix convention for many compression formats #2822 (@lhoestq)
• Support streaming datasets that use pathlib #2874 (@albertvillanova)
• Extend support for streaming datasets that use pathlib.Path stem/suffix #2880 (@albertvillanova)
• Extend support for streaming datasets that use pathlib.Path.glob #2876 (@albertvillanova)

Metrics changes

• Update: BERTScore - Add support for fast tokenizer #2770 (@mariosasko)
• Fix: Sacrebleu - Fix sacrebleu tokenizers #2739 #2778 #2779 (@albertvillanova)

Dataset cards

• Updated dataset description of DaNE #2789 (@KennethEnevoldsen)
• Update ELI5 README.md #2848 (@odellus)

General improvements and bug fixes

• Update release instructions #2740 (@albertvillanova)
• Raise ManualDownloadError when loading a dataset that requires previous manual download #2758 (@albertvillanova)
• Allow PyArrow from source #2769 (@patrickvonplaten)
• fix typo (ShuffingConfig -> ShufflingConfig) #2766 (@daleevans)
• Fix typo in test_dataset_common #2790 (@nateraw)
• Fix type hint for data_files #2793 (@albertvillanova)
• Bump tqdm version #2814 (@mariosasko)
• Use packaging to handle versions #2777 (@albertvillanova)
• Tiny typo fixes of "fo" -> "of" #2815 (@aronszanto)
• Rename The Pile subsets #2817 (@lhoestq)
• Fix IndexError by ignoring empty RecordBatch #2834 (@lhoestq)
• Fix defaults in cache_dir docstring in load.py #2824 (@mariosasko)
• Fix extraction protocol inference from urls with params #2843 (@lhoestq)
• Fix caching when moving script #2854 (@lhoestq)
• Fix windows CI CondaError #2855 (@lhoestq)
• fix: 🐛 remove URL's query string only if it's ?dl=1 #2856 (@severo)
• Update column_names showed as :func: in exploring.st #2851 (@ClementRomac)
• Fix s3fs version in CI #2858 (@lhoestq)
• Fix three typos in two files for documentation #2870 (@leny-mi)
• Move checks from _map_single to map #2660 (@mariosasko)
• fix regex to accept negative timezone #2847 (@jadermcs)
• Prevent .map from using multiprocessing when loading from cache #2774 (@thomasw21)
• Fix null sequence encoding #2900 (@lhoestq)

1.11.0

Datasets Changes

• New: Add Russian SuperGLUE #2668 (@slowwavesleep)
• New: Add Disfl-QA #2473 (@bhavitvyamalik)
• New: Add TimeDial #2476 (@bhavitvyamalik)
• Fix: Enumerate all ner_tags values in WNUT 17 dataset #2713 (@albertvillanova)
• Fix: Update WikiANN data URL #2710 (@albertvillanova)
• Fix: Update PAN-X data URL in XTREME dataset #2715 (@albertvillanova)
• Fix: C4 - en subset by modifying dataset_info with correct validation infos #2723 (@thomasw21)

General improvements and bug fixes

• fix: 🐛 change string format to allow copy/paste to work in bash #2694 (@severo)
• Update BibTeX entry #2706 (@albertvillanova)
• Print absolute local paths in load_dataset error messages #2684 (@mariosasko)
• Add support for disable_progress_bar on Windows #2696 (@mariosasko)
• Ignore empty batch when writing #2698 (@pcuenca)
• Fix shuffle on IterableDataset that disables batching in case any functions were mapped #2717 (@amankhandelia)
• fix: 🐛 fix two typos #2720 (@severo)
• Docs details #2690 (@severo)
• Deal with the bad check in test_load.py #2721 (@mariosasko)
• Pass use_auth_token to request_etags #2725 (@albertvillanova)
• Typo fix tokenize_exemple #2726 (@shabie)
• Fix IndexError while loading Arabic Billion Words dataset #2729 (@albertvillanova)
• Add missing parquet known extension #2733 (@lhoestq)

1.10.2

The error message to tell which dataset config name to load was not displayed:

• Fix pick default config name message #2704 (@lhoestq)

Docstrings:

• Fix download_mode docstrings #2701 (@albertvillanova)

1.10.1

• Fix minimum tqdm version and import on Colab #2697 (@nateraw)
• Fix OSCAR Esperanto #2693 (@lhoestq)

1.10.0

Datasets Features

• Support remote data files #2616 (@albertvillanova)
  This allows to pass URLs of remote data files to any dataset loader:

  load_dataset("csv", data_files={"train": [url_to_one_csv_file, url_to_another_csv_file...]})

  This works for all these dataset loaders:
  • text
  • csv
  • json
  • parquet
  • pandas
• Streaming from remote text/json/csv/parquet/pandas files:
  When you pass URLs to a dataset loader, you can enable streaming mode with streaming=True. Main contributions:
  • Streaming for the Pandas loader #2636 (@lhoestq)
  • Streaming for the CSV loader #2635 (@lhoestq)
  • Streaming for the Json loader #2608 (@albertvillanova) #2638 (@lhoestq)
• Faster search_batch for ElasticsearchIndex due to threading #2581 (@mwrzalik)
• Delete extracted files when loading dataset #2631 (@albertvillanova)

Datasets Changes

• Fix: C4 - fix expected files list #2682 (@lhoestq)
• Fix: SQuAD - fix misalignment #2586 (@albertvillanova)
• Fix: omp - fix DuplicatedKeysError#2603 (@albertvillanova)
• Fix: wi_locness - potential DuplicatedKeysError #2609 (@albertvillanova)
• Fix: LibriSpeech - potential DuplicatedKeysError #2672 (@albertvillanova)
• Fix: SQuAD - potential DuplicatedKeysError #2673 (@albertvillanova)
• Fix: Blog Authorship Corpus - fix split sizes and text encoding #2685 (@albertvillanova)

Dataset Tasks

• Add speech processing tasks #2620 (@lewtun)
• Update ASR tags #2633 (@lewtun)
• Inject ASR template for lj_speech dataset #2634 (@albertvillanova)
• Add ASR task for SUPERB #2619 (@lewtun)
• add image-classification task template #2632 (@nateraw)

Metrics Changes

• New: wiki_split #2623 (@bhadreshpsavani)
• Update: accuracy,f1,precision,recall - Support multilabel metrics #2589 (@albertvillanova)
• Fix: sacrebleu - fix parameter name #2674 (@albertvillanova)

General improvements and bug fixes

• Fix BibTeX entry #2594 (@albertvillanova)
• Fix test_is_small_dataset #2588 (@albertvillanova)
• Remove import of transformers #2602 (@albertvillanova)
• Make any ClientError trigger retry in streaming mode (e.g. ClientOSError) #2605 (@lhoestq)
• Fix filter with multiprocessing in case all samples are discarded #2601 (@mxschmdt)
• Remove redundant prepare_module #2597 (@albertvillanova)
• Create ExtractManager #2295 (@albertvillanova)
• Return Python float instead of numpy.float64 in sklearn metrics #2612 (@lewtun)
• Use ndarray.item instead of ndarray.tolist #2613 (@lewtun)
• Convert numpy scalar to python float in Pearsonr output #2614 (@lhoestq)
• Fix missing EOL issue in to_json for old versions of pandas #2617 (@lhoestq)
• Use correct logger in metrics.py #2626 (@mariosasko)
• Minor fix tests with Windows paths #2627 (@albertvillanova)
• Use ETag of remote data files #2628 (@albertvillanova)
• More consistent naming #2611 (@mariosasko)
• Refactor patching to specific submodule #2639 (@albertvillanova)
• Fix docstrings #2640 (@albertvillanova)
• Fix anchor in README #2647 (@mariosasko)
• Fix logging docstring #2652 (@mariosasko)
• Allow dataset config kwargs to be None #2659 (@lhoestq)
• Use prefix to allow exceed Windows MAX_PATH #2621 (@albertvillanova)
• Use tqdm from tqdm_utils #2667 (@mariosasko)
• Increase json reader block_size automatically #2676 (@lhoestq)
• Parallelize ETag requests #2675 (@lhoestq)
• Fix bad config ids that name cache directories #2686 (@lhoestq)
• Minor documentation fix #2687 (@slowwavesleep)

Dataset Cards

• Add missing WikiANN language tags #2610 (@albertvillanova)
• feat: 🎸 add paperswithcode id for qasper dataset #2680 (@severo)

Docs

• Update processing.rst with other export formats #2599 (@TevenLeScao)

1.9.0

Datasets Changes

• New: C4 #2575 #2592 (@lhoestq)
• New: mC4 #2576 (@lhoestq)
• New: MasakhaNER #2465 (@dadelani)
• New: Eduge #2492 (@enod)
• Update: xor_tydi_qa - update version #2455 (@cccntu)
• Update: kilt-TriviaQA - original answers #2410 (@PaulLerner)
• Update: udpos - change features structure #2466 (@JerryIsHere)
• Update: WebNLG - update checksums #2558 (@lhoestq)
• Fix: climate fever - adjusting indexing for the labels. #2464 (@drugilsberg)
• Fix: proto_qa - fix download link #2463 (@mariosasko)
• Fix: ProductReviews - fix label parsing #2530 (@yavuzKomecoglu)
• Fix: DROP - fix DuplicatedKeysError #2545 (@albertvillanova)
• Fix: code_search_net - fix keys #2555 (@lhoestq)
• Fix: discofuse - fix link cc #2541 (@VictorSanh)
• Fix: fever - fix keys #2557 (@lhoestq)

Datasets Features

• Dataset Streaming #2375 #2582 (@lhoestq)
  • Fast download and process your data on-the-fly when iterating over your dataset
  • Works with huge datasets like OSCAR, C4, mC4 and hundreds of other datasets
• JAX integration #2502 (@lhoestq)
• Add Parquet loader + from_parquet and to_parquet #2537 (@lhoestq)
• Implement ClassLabel encoding in JSON loader #2468 (@albertvillanova)
• Set configurable downloaded datasets path #2488 (@albertvillanova)
• Set configurable extracted datasets path #2487 (@albertvillanova)
• Add align_labels_with_mapping function #2457 (@lewtun) #2510 (@lhoestq)
• Add interleave_datasets for map-style datasets #2568 (@lhoestq)
• Add load_dataset_builder #2500 (@mariosasko)
• Support Zstandard compressed files #2578 (@albertvillanova)

Task templates

• Add task templates for tydiqa and xquad #2518 (@lewtun)
• Insert text classification template for Emotion dataset #2521 (@lewtun)
• Add summarization template #2529 (@lewtun)
• Add task template for automatic speech recognition #2533 (@lewtun)
• Remove task templates if required features are removed during Dataset.map #2540 (@lewtun)
• Inject templates for ASR datasets #2565 (@lewtun)

General improvements and bug fixes

• Allow to use tqdm>=4.50.0 #2482 (@lhoestq)
• Use gc.collect only when needed to avoid slow downs #2483 (@lhoestq)
• Allow latest pyarrow version #2490 (@albertvillanova)
• Use default cast for sliced list arrays if pyarrow >= 4 #2497 (@albertvillanova)
• Add Zenodo metadata file with license #2501 (@albertvillanova)
• add tensorflow-macos support #2493 (@slayerjain)
• Keep original features order #2453 (@albertvillanova)
• Add course banner #2506 (@sgugger)
• Rearrange JSON field names to match passed features schema field names #2507 (@albertvillanova)
• Fix typo in MatthewsCorrelation class name #2517 (@albertvillanova)
• Use scikit-learn package rather than sklearn in setup.py #2525 (@lesteve)
• Improve performance of pandas arrow extractor #2519 (@albertvillanova)
• Fix fingerprint when moving cache dir #2509 (@lhoestq)
• Replace bad n>1M size tag #2527 (@lhoestq)
• Fix dev version #2531 (@lhoestq)
• Sync with transformers disabling NOTSET #2534 (@albertvillanova)
• Fix logging levels #2544 (@albertvillanova)
• Add support for Split.ALL #2259 (@mariosasko)
• Raise FileNotFoundError in WindowsFileLock #2524 (@mariosasko)
• Make numpy arrow extractor faster #2505 (@lhoestq)
• fix Dataset.map when num_procs > num rows #2566 (@connor-mccarthy)
• Add ASR task and new languages to resources #2567 (@lewtun)
• Filter expected warning log from transformers #2571 (@albertvillanova)
• Fix BibTeX entry #2579 (@albertvillanova)
• Fix Counter import #2580 (@albertvillanova)
• Add aiohttp to tests extras require #2587 (@albertvillanova)
• Add language tags #2590 (@lewtun)
• Support pandas 1.3.0 read_csv #2593 (@lhoestq)

Dataset cards

• Updated Dataset Description #2420 (@binny-mathew)
• Update DatasetMetadata and ReadMe #2436 (@gchhablani)
• CRD3 dataset card #2515 (@wilsonyhlee)
• Add license to the Cambridge English Write & Improve + LOCNESS dataset card #2546 (@lhoestq)
• wi_locness: reference latest leaderboard on codalab #2584 (@aseifert)

Docs

• no s at load_datasets #2479 (@julien-c)
• Fix docs custom stable version #2477 (@albertvillanova)
• Improve Features docs #2535 (@albertvillanova)
• Update README.md #2414 (@cryoff)
• Fix FileSystems documentation #2551 (@connor-mccarthy)
• Minor fix in loading metrics docs #2562 (@albertvillanova)
• Minor fix docs format for bertscore #2570 (@albertvillanova)
• Add streaming in load a dataset docs #2574 (@lhoestq)

1.8.0

Datasets Changes

• New: Microsoft CodeXGlue Datasets #2357 (@madlag @ncoop57)
• New: KLUE benchmark #2416 (@jungwhank)
• New: HendrycksTest #2370 (@andyzoujm)
• Update: xor_tydi_qa - update url to v1.1 #2449 (@cccntu)
• Fix: adversarial_qa - DuplicatedKeysError #2433 (@mariosasko)
• Fix: bn_hate_speech and covid_tweets_japanese - fix broken URLs for #2445 (@lewtun)
• Fix: flores - fix download link #2448 (@mariosasko)

Datasets Features

• Add desc parameter in map for DatasetDict object #2423 (@bhavitvyamalik)
• Support sliced list arrays in cast #2461 (@lhoestq)
  • Dataset.cast can now change the feature types of Sequence fields
• Revert default in-memory for small datasets #2460 (@albertvillanova) Breaking:
  • we used to have the datasets IN_MEMORY_MAX_SIZE to 250MB
  • we changed this to zero: by default datasets are loaded from the disk with memory mapping and not copied in memory
  • users can still set keep_in_memory=True when loading a dataset to load it in memory

Datasets Cards

• adds license information for DailyDialog. #2419 (@aditya2211)
• add english language tags for ~100 datasets #2442 (@VictorSanh)
• Add copyright info to MLSUM dataset #2427 (@PhilipMay)
• Add copyright info for wiki_lingua dataset #2428 (@PhilipMay)
• Mention that there are no answers in adversarial_qa test set #2451 (@lhoestq)

General improvements and bug fixes

• Add DOI badge to README #2411 (@albertvillanova)
• Make datasets PEP-561 compliant #2417 (@SBrandeis)
• Fix save_to_disk nested features order in dataset_info.json #2422 (@lhoestq)
• Fix CI six installation on linux #2432 (@lhoestq)
• Fix Docstring Mistake: dataset vs. metric #2425 (@PhilipMay)
• Fix NQ features loading: reorder fields of features to match nested fields order in arrow data #2438 (@lhoestq)
• doc: fix typo HF_MAX_IN_MEMORY_DATASET_SIZE_IN_BYTES #2421 (@borisdayma)
• add utf-8 while reading README #2418 (@bhavitvyamalik)
• Better error message when trying to access elements of a DatasetDict without specifying the split #2439 (@lhoestq)
• Rename config and environment variable for in memory max size #2454 (@albertvillanova)
• Add version-specific BibTeX #2430 (@albertvillanova)
• Fix cross-reference typos in documentation #2456 (@albertvillanova)
• Better error message when using the wrong load_from_disk #2437 (@lhoestq)

Experimental and work in progress: Format a dataset for specific tasks

• Update text classification template labels in DatasetInfo post_init #2392 (@lewtun)
• Insert task templates for text classification #2389 (@lewtun)
• Rename QuestionAnswering template to QuestionAnsweringExtractive #2429 (@lewtun)
• Insert Extractive QA templates for SQuAD-like datasets #2435 (@lewtun)

1.7.0

Dataset Changes

• New: NLU evaluation data #2238 (@dkajtoch)
• New: Add SLR32, SLR52, SLR53 to OpenSLR #2241, #2311 (@cahya-wirawan)
• New: Bbaw egyptian #2290 (@phiwi)
• New: GooAQ #2260 (@bhavitvyamalik)
• New: SubjQA #2302 (@lewtun)
• New: Ascent KB #2341, #2349 (@phongnt570)
• New: HLGD #2325 (@tingofurro)
• New: Qasper #2346 (@cceyda)
• New: ConvQuestions benchmark #2372 (@PhilippChr)
• Update: Wikihow - Clarify how to load wikihow #2240 (@albertvillanova)
• Update multi_woz_v22 - update checksum #2281 (@lhoestq)
• Update: OSCAR - Set encoding in OSCAR dataset #2321 (@albertvillanova)
• Update: XTREME - Enable auto-download for PAN-X / Wikiann domain in XTREME #2326 (@lewtun)
• Update: GEM - the DART file checksums in GEM #2334 (@yjernite)
• Update: web_science - fixed download link #2338 (@bhavitvyamalik)
• Update: SNLI, MNLI- README updated for SNLI, MNLI #2364 (@bhavitvyamalik)
• Update: conll2003 - correct labels #2369 (@philschmid)
• Update: offenseval_dravidian - update citations #2385 (@adeepH)
• Update: ai2_arc - Add dataset tags #2405 (@OyvindTafjord)
• Fix: newsph_nli - test data added, dataset_infos updated #2263 (@bhavitvyamalik)
• Fix: hyperpartisan news detection - Remove getchildren #2367 (@ghomasHudson)
• Fix: indic_glue - Fix number of classes in indic_glue sna.bn dataset #2397 (@albertvillanova)
• Fix: head_qa - Fix keys #2408 (@lhoestq)

Dataset Features

• Implement Dataset add_item #1870 (@albertvillanova)
• Implement Dataset add_column #2145 (@albertvillanova)
• Implement Dataset to JSON #2248, #2352 (@albertvillanova)
• Add rename_columnS method #2312 (@SBrandeis)
• add desc to tqdm in Dataset.map() #2374 (@bhavitvyamalik)
• Add env variable HF_MAX_IN_MEMORY_DATASET_SIZE_IN_BYTES #2399, #2409 (@albertvillanova)

Metric Changes

• New: CUAD metrics #2273 (@bhavitvyamalik)
• New: Matthews/Pearson/Spearman correlation metrics #2328 (@lhoestq)
• Update: CER - Docs, CER above 1 #2342 (@borisdayma)

General improvements and bug fixes

• Update black #2265 (@lhoestq)
• Fix incorrect update_metadata_with_features calls in ArrowDataset #2258 (@mariosasko)
• Faster map w/ input_columns & faster slicing w/ Iterable keys #2246 (@norabelrose)
• Don't use pyarrow 4.0.0 since it segfaults when casting a sliced ListArray of integers #2268 (@lhoestq)
• Fix query table with iterable #2269 (@lhoestq)
• Perform minor refactoring: use config #2253 (@albertvillanova)
• Update format, fingerprint and indices after add_item #2254 (@lhoestq)
• Always update metadata in arrow schema #2274 (@lhoestq)
• Make tests run faster #2266 (@lhoestq)
• Fix metadata validation with config names #2286 (@lhoestq)
• Fixed typo seperate->separate #2292 (@laksh9950)
• Allow collaborators to self-assign issues #2289 (@albertvillanova)
• Mapping in the distributed setting #2298 (@TevenLeScao)
• Fix conda release #2309 (@lhoestq)
• Fix incorrect version specification for the pyarrow package #2317 (@cemilcengiz)
• Set default name in init_dynamic_modules #2320 (@albertvillanova)
• Fix duplicate keys #2333 (@lhoestq)
• Add note about indices mapping in save_to_disk docstring #2332 (@lhoestq)
• Metadata validation #2107 (@theo-m)
• Add Validation For README #2121 (@gchhablani)
• Fix overflow issue in interpolation search #2336 (@mariosasko)
• Datasets cli improvements #2315 (@mariosasko)
• Add key type and duplicates verification with hashing #2245 (@NikhilBartwal)
• More consistent copy logic #2340 (@mariosasko)
• Update README vallidation rules #2353 (@gchhablani)
• normalized TOCs and titles in data cards #2355 (@yjernite)
• simpllify faiss index save #2351 (@Guitaricet)
• Allow "other-X" in licenses #2368 (@gchhablani)
• Improve ReadInstruction logic and update docs #2261 (@mariosasko)
• Disallow duplicate keys in yaml tags #2379 (@lhoestq)
• maintain YAML structure reading from README #2380 (@bhavitvyamalik)
• add dataset card title #2381 (@bhavitvyamalik)
• Add tests for dataset cards #2348 (@gchhablani)
• Improve example in rounding docs #2383 (@mariosasko)
• Paperswithcode dataset mapping #2404 (@julien-c)
• Free datasets with cache file in temp dir on exit #2403 (@mariosasko)

Experimental and work in progress: Format a dataset for specific tasks

• Task formatting for text classification & question answering #2255 (@SBrandeis)
• Add check for task templates on dataset load #2390 (@lewtun)
• Add args description to DatasetInfo #2384 (@lewtun)
• Improve task api code quality #2376 (@mariosasko)

1.6.2

Fix memory issue: don't copy recordbatches in memory during a table deepcopy #2291 (@lhoestq)
This affected methods like concatenate_datasets, multiprocessed map and load_from_disk.

Breaking change:

• when using Dataset.map with the input_columns parameter, the resulting dataset will only have the columns from input_columns and the columns added by the map functions. The other columns are discarded.