HKUDS/Vibe-Trading · error · CashFlowIngestError

row : date does not match date_format=

Error message

{path} row {row_number}: date {raw!r} does not match date_format={date_format!r}

What it means

Raised by _parse_date when an explicit date_format was supplied but the cell does not match it under datetime.strptime. The message echoes both the raw value and the format string so the mismatch is immediately visible.

Solutions

Compare the raw value with the format string in the message and correct the format (e.g. add %H:%M or fix directive order)
If the file is actually ISO, drop date_format and let normalize_date handle it
If the file mixes formats, normalize dates in the source or split the file by format
Check for stray characters like weekday names or timezones and extend the format accordingly

Example fix

# before
load_cashflows('us.csv', date_format='%d/%m/%Y')
# after
load_cashflows('us.csv', date_format='%m/%d/%Y')

Defensive patterns

Strategy: validation

Validate before calling

from datetime import datetime
sample = [r[date_col] for r in rows[:20] if r.get(date_col)]
for fmt in ('%m/%d/%Y', '%d/%m/%Y', '%Y-%m-%d'):
    if all(try_strptime(v, fmt) for v in sample):
        chosen = fmt; break
else:
    raise ValueError('no single date_format fits sample')

Type guard

def matches_format(text: str, fmt: str) -> bool:
    try:
        datetime.strptime(text.strip(), fmt); return True
    except ValueError:
        return False

Try / catch

try:
    load_cashflows(p, date_format=fmt)
except CashFlowIngestError as e:
    if 'does not match date_format' in str(e):
        fmt = infer_format_from_sample(p); load_cashflows(p, date_format=fmt)

Prevention

Probe a sample of dates with strptime to confirm the format before full load
Store the per-source date_format in config
Watch for rows that deviate from the file's dominant format

When it happens

Trigger: load_cashflows(path, date_format='%m/%d/%Y') on a file containing '05/06/2024' mismatch or a value like '2024-01-05' when the format expects US ordering; any strptime-incompatible cell when date_format is non-None.

Common situations: Wrong format string for the actual export (e.g. %d/%m/%Y vs %m/%d/%Y); mixed-format rows in one file; format string with literal text (like 'T' or timezone suffix) missing; leading/trailing whitespace handled but internal mismatches not.

Related errors

AI-assisted analysis of HKUDS/Vibe-Trading@80ffdda44c (2026-08-28). Data as JSON: /api/errors/4baaee6754c7fe6f. Report an issue: GitHub.

Appendix: source

Thrown at agent/src/entities/ingest.py:253

        raw: Raw cell text.
        date_format: ``strptime`` format, or ``None`` to require ISO-8601.
        path: File path, used only for error messages.
        row_number: 1-based data row number, used only for error messages.

    Returns:
        The parsed ``datetime.date``.

    Raises:
        CashFlowIngestError: If the cell is blank or does not parse.
    """
    text = (raw or "").strip()
    if not text:
        raise CashFlowIngestError(f"{path} row {row_number}: date is blank")
    if date_format:
        try:
            return datetime.strptime(text, date_format).date()
        except ValueError as exc:
            raise CashFlowIngestError(
                f"{path} row {row_number}: date {raw!r} does not match "
                f"date_format={date_format!r}"
            ) from exc
    try:
        return normalize_date(text)
    except ValueError as exc:
        raise CashFlowIngestError(
            f"{path} row {row_number}: date {raw!r} is not ISO-8601 "
            "(YYYY-MM-DD). Pass date_format=... explicitly; regional formats "
            "are not guessed because day-first and month-first cannot be told "
            "apart from the data."
        ) from exc


def _read_rows(
    path: Path, delimiter: str | None, encoding: str
) -> tuple[list[str], list[dict[str, str]]]:
    """Read a delimited text file into a header and a list of row mappings.

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