f/scripts/clean_multivintage.py
Greg Pomerantz 3c5bee96ce Clean multi-vintage 'ctime' files: 1,065 files, 2.2M stale rows
Some dump files carry a trailing 'ctime' column: an older pipeline
appended a FULL re-download of the symbol per download (up to ~28
vintages per date, 2019-2022). The consumer keeps the last row per date,
so it silently used stale (~2021) vintages where Yahoo later revised
values. scripts/clean_multivintage.py keeps, per date, the rows from the
newest ctime (event files keep distinct same-day amounts; history/split
keep the single newest row), drops the ctime column, sorts by date.
Applied to the data root and overrides/frozen (which carried the same
artifact): 1,065 files, 2,202,712 stale rows dropped.

Also: stripped 3 UTF-8 BOMs (teg/lo/krft), refreshed the event backup
with the cleaned files, and re-ran the double-listing scan: category C
(83 symbols, 18,636 repeated within-file rows) is fully explained by the
multi-vintage artifact and is now gone; A (6,589 pairs, corrected) and
B (12,366 pairs, open review list) are unchanged. Whole-set structural
QC after cleaning: 0 duplicate dates, 3 syms/15 rows of OHLC invariant
violations, 15 syms/2,897 rows of non-positive prices (mostly
long-delisted tickers), 8 unsorted files (reader sorts).
2026-08-31 22:25:02 -04:00

101 lines
4.0 KiB
Python

#!/usr/bin/env python3
"""Clean multi-vintage ('ctime') files in the data dump.
Some files carry an extra trailing 'ctime' column: each re-download of the
symbol APPENDED a full copy of the history stamped with the download time
(up to ~28 vintages per date, 2019-2022). The consumer keeps the LAST row
per date, so with mixed vintages it silently used a stale (~2021) vintage.
Fix, per file: for each date keep only the rows from the newest ctime
(several different amounts at the newest ctime are a legitimate same-day
pair and are all kept; exact (date, ctime) duplicates collapse to the last
row). The ctime column is dropped, rows sorted by date. Idempotent.
Also strips UTF-8 BOMs. Applies to the data root and overrides/frozen
(the frozen copies shadow the root and carry the same artifact).
Usage: python3 scripts/clean_multivintage.py [--data DIR] [--frozen DIR]
[--dry-run]
"""
import argparse
from pathlib import Path
ROOT_DEFAULT = Path("~/prog/fin/stocks").expanduser()
FROZEN_DEFAULT = Path(__file__).resolve().parent.parent / "overrides" / "frozen"
SUFFIXES = ("history", "dividend", "capitalGain", "split")
def clean_lines(lines: list[str], one_per_date: bool = False) -> list[str] | None:
"""Return cleaned lines, or None if the file has no ctime column.
one_per_date (history/split): the newest-vintage row wins per date;
event files keep every distinct amount at the newest ctime (a fund can
genuinely pay several distributions the same day)."""
header = lines[0].rstrip("\n").split(",")
if "ctime" not in header:
return None
ci = header.index("ctime")
body = [l.split(",") for l in lines[1:] if l.strip()]
by_date: dict[str, list[tuple[str, int, list[str]]]] = {}
for i, a in enumerate(body):
if len(a) < 2:
continue
date = a[0][:10]
ctime = a[ci] if ci < len(a) else ""
vals = a[1:ci] + a[ci + 1:] if ci < len(a) else a[1:]
by_date.setdefault(date, []).append((ctime, i, vals))
out = []
for date in sorted(by_date):
rows = [r for r in by_date[date] if r[0] == max(x[0] for x in by_date[date])]
if one_per_date:
out.append(date + "," + ",".join(rows[-1][2]))
continue
# last occurrence of each distinct row (keeps legitimate same-day
# pairs with different amounts, collapses exact repeats)
last_pos = {}
for j, (_, _, vals) in enumerate(rows):
last_pos[tuple(vals)] = j
for j in sorted(last_pos.values()):
out.append(date + "," + ",".join(rows[j][2]))
return [",".join(header[:ci] + header[ci + 1:])] + out
def process(dirs: list[Path], dry: bool) -> tuple[int, int]:
n_files = n_rows = 0
for d in dirs:
if not d.is_dir():
continue
for sfx in SUFFIXES:
for f in sorted(d.glob(f"*-{sfx}.csv")):
raw = f.read_bytes()
bom = raw.startswith(b"\xef\xbb\xbf")
text = raw.decode("utf-8", "replace")
lines = text.splitlines()
out = clean_lines(lines, one_per_date=sfx in ("history", "split"))
changed = out is not None or bom
if not changed:
continue
n_files += 1
if out is None:
out = lines
before = max(len(lines) - 1, 0)
n_rows += before - max(len(out) - 1, 0)
if not dry:
f.write_bytes(("\n".join(out) + "\n").encode("utf-8"))
return n_files, n_rows
def main() -> int:
ap = argparse.ArgumentParser()
ap.add_argument("--data", type=Path, default=ROOT_DEFAULT)
ap.add_argument("--frozen", type=Path, default=FROZEN_DEFAULT)
ap.add_argument("--dry-run", action="store_true")
args = ap.parse_args()
nf, nr = process([args.data, args.frozen], args.dry_run)
print(f"{'would clean' if args.dry_run else 'cleaned'} {nf} files, "
f"{'would drop' if args.dry_run else 'dropped'} {nr} stale-vintage rows")
return 0
if __name__ == "__main__":
main()