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Short answer

Loading defaults to the train split. You can request other splits, percentage slices, or build splits with train_test_split. [S1][S2]

Points

• Percentage slices select part of a split. [S1]
• revision pins a dataset version. [S1]
• train_test_split creates train/test splits when missing. [S2]

Claims

• id: C1 claim: Datasets load into the train split by default. source: S1 evidence: "A dataset loads by default all the data into the train split"
• id: C2 claim: You can select a percentage of a split. source: S1 evidence: "Or select a percentage of a split with"
• id: C3 claim: revision selects the dataset version to load. source: S1 evidence: "Use the revision parameter to specify the dataset version you want to load"
• id: C4 claim: train_test_split creates train and test splits. source: S2 evidence: "The train_test_split() function creates train and test splits"

Sources

• [S1] Load · Hugging Face. Hugging Face (Datasets docs). https://huggingface.co/docs/datasets/loading . License: Apache-2.0 (huggingface/datasets docs). Accessed 2026-11-05.
• [S2] Process. Hugging Face. https://huggingface.co/docs/datasets/process . License: Apache-2.0 (huggingface/datasets docs). Accessed 2026-11-05.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted).

Source notice: Hugging Face Datasets documentation, Apache License 2.0 (https://github.com/huggingface/datasets/blob/main/LICENSE).

@misc{iil_note_rqjrnnas,
  author = {{iinventedlight}},
  title = {{Load part of a split in Hugging Face Datasets}},
  howpublished = {iinventedlight Library},
  year = {2026},
  date = {2026-11-04},
  url = {https://iinventedlight.com/library/notes/hf-datasets-split-slicing/},
  note = {Permanent ID iil:note:rqjrnnas. License: CC-BY-4.0.},
}

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