Files
xtrain/scripts/fineweb_to_txt.py
Gahow Wang 7e5ea9976b data: FineWeb-edu parquet->txt prep script (Scaling v6)
v6 broadens data from TinyStories to FineWeb-edu (HuggingFaceFW/fineweb-edu
sample/10BT) while freezing the v4/v5 arch. scripts/fineweb_to_txt.py streams
the parquet text column row-group by row-group and joins docs with
<|endoftext|> so xtrain's existing Corpus loader (gpt2 BPE, u16 cache) handles
it unchanged. Corpus .txt/.parquet/.u16.bin stay dash5-only (gitignored).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-16 19:04:45 +08:00

60 lines
2.1 KiB
Python

#!/usr/bin/env python3
"""FineWeb-edu parquet -> plain UTF-8 .txt for xtrain's Corpus loader (Scaling v6).
v0-v5 trained on TinyStories; v6 broadens the data to FineWeb-edu
(HuggingFaceFW/fineweb-edu, the `sample/10BT` subset) to isolate the
data-source variable while keeping the v4/v5 architecture fixed.
xtrain's `Corpus::load` (crates/xtrain-train/src/data.rs) reads a UTF-8 text
file and tokenizes it with the gpt2 BPE; it treats `<|endoftext|>` as the
document boundary (the gpt2 tokenizer emits id 50256 for it). This script
extracts the `text` column from one or more FineWeb-edu parquet shards and
writes each document followed by `<|endoftext|>`, producing exactly that
format. Reads row-group by row-group so memory stays bounded regardless of
shard size.
Usage (on dash5, in data/):
python3 scripts/fineweb_to_txt.py OUT.txt SHARD1.parquet [SHARD2.parquet ...]
The corpus / .txt / .u16.bin caches are multi-GB and live on dash5 only
(gitignored); only this script is committed.
"""
import sys
import pyarrow.parquet as pq
EOS = "<|endoftext|>"
def main() -> None:
if len(sys.argv) < 3:
sys.exit(f"usage: {sys.argv[0]} OUT.txt SHARD.parquet [SHARD.parquet ...]")
out_path = sys.argv[1]
shards = sys.argv[2:]
docs = 0
chars = 0
with open(out_path, "w", encoding="utf-8") as out:
for shard in shards:
pf = pq.ParquetFile(shard)
n_rg = pf.num_row_groups
print(f"{shard}: {pf.metadata.num_rows} rows, {n_rg} row groups", flush=True)
for rg in range(n_rg):
col = pf.read_row_group(rg, columns=["text"]).column("text")
for s in col:
text = s.as_py()
if text is None:
continue
out.write(text)
out.write(EOS)
docs += 1
chars += len(text)
print(f" done {shard}: cumulative {docs} docs", flush=True)
print(f"wrote {out_path}: {docs} docs, {chars} text chars "
f"(+ {docs} x '{EOS}' separators)", flush=True)
if __name__ == "__main__":
main()