Hugging Face `select`, `filter`, and `shuffle` can retain a physical
Arrow table while storing logical row selection/order in an indices
table. Ingesting the physical table then silently writes excluded rows
or the wrong order and can lose duplicate selections.
Read indexed datasets through bounded Arrow-format iteration, and keep
the existing direct batch path for datasets without indices. Apply the
same conversion to sync/async table creation and additions, including
DatasetDict splits. The conversion does not mutate the user's formatting
settings.
Regression coverage includes reordered/duplicate selections, filtering,
shuffling, empty selections, projected numpy/pandas/Arrow formatting,
DatasetDicts, rescanning, and bounded batches.
Validation on base d864e7198f with its
byte-identical native/config:
- Python 3.11 full CI test selection: 1564 passed, 36 skipped, 68
deselected; 162.51s pytest /171.68s wall.
- Python 3.13 full CI test selection: 1521 passed, 37 skipped, 68
deselected; 160.32s pytest /163.74s wall. Optional HF tests were skipped
in this environment.
- Python 3.13 complete doctest command: 71 passed, 6 skipped; 8.42s
pytest /12.14s wall.
- Python 3.11 HF regression module from a candidate wheel: 43 passed;
the same regression module on the unchanged baseline gives 24 failed /19
passed.
- Ruff check/format, repository pre-commit hooks, pyright with the
source import path, and `git diff --check` passed.
This is a Python-only change. Native binaries were reused from the
verified baseline; no new native build or external-service integration
tests were run. The separate schema-metadata preservation change in
#4451 addresses a different conversion defect.
The target branch currently includes newer native changes than the
verified base. Latest-main native compatibility, Linux CI, and
remote-service tests remain for CI/maintainer validation. Prepared with
AI assistance (gpt-6.1-sol).
HuggingFace Dataset is written as arrow batches.
For DatasetDict, all splits are written with a "split" column appended.
- [x] what if the dataset schema already has a `split` column
- [x] add unit tests
LeonSGP
Will Jones
Chang She