OpenBB-finance/OpenBB · error · OpenBBError

Could not find the header row in the CSV data.

Error message

Could not find the header row in the CSV data.

What it means

Raised while parsing the Federal Reserve's Svensson CSV: the parser scans every line for one starting with 'Date,' to locate the real header (the CSV ships with preamble rows), and none was found. This is an OpenBBError — a hard failure indicating the upstream file format changed, not a query problem.

Source

Thrown at openbb_platform/providers/federal_reserve/openbb_federal_reserve/models/svensson_yield_curve.py:1154

                elif series_type == "forward_1y":
                    allowed_fields.update({"sven1f01", "sven1f04", "sven1f09"})
                elif series_type == "parameters":
                    allowed_fields.update(
                        {"beta0", "beta1", "beta2", "beta3", "tau1", "tau2"}
                    )
                else:
                    # Individual column selection
                    allowed_fields.add(series_type)

        # Find the line starting with "Date," which is the real column header.
        lines = data.split("\n")
        header_index = next(
            (i for i, line in enumerate(lines) if line.startswith("Date,")),
            None,
        )

        if header_index is None:
            raise OpenBBError("Could not find the header row in the CSV data.")

        csv_content = "\n".join(lines[header_index:])
        reader = csv.DictReader(StringIO(csv_content))
        results: list[FederalReserveSvenssonData] = []

        for row in reader:
            date_str = row.get("Date", "")
            if not date_str:
                continue

            try:
                row_date = datetime.strptime(date_str, "%Y-%m-%d").date()
            except ValueError:
                continue

            if query.start_date and row_date < query.start_date:
                continue

View on GitHub (pinned to 3e071fcc2c)

Solutions

1. Download the same CSV the provider uses and inspect its first lines to see how the header changed.
2. Update the provider (pip install -U openbb-federal-reserve) — format changes are usually patched quickly.
3. If patching locally, adjust the header detection (line.startswith('Date,')) to the new header text, including stripping a BOM.

Example fix

// before
header_index = next((i for i, line in enumerate(lines) if line.startswith('Date,')), None)
// after (tolerate BOM / whitespace)
header_index = next((i for i, line in enumerate(lines) if line.lstrip('\ufeff').startswith('Date,')), None)

first_lines = data.split('\n')[:20]
assert any(l.startswith('Date,') for l in first_lines), 'upstream CSV header changed'

from openbb_core.app.model.abstract.error import OpenBBError
try:
    res = obb.economy.svensson_yield_curve(provider='federal_reserve')
except OpenBBError as e:
    if 'header row' in str(e):
        raise RuntimeError('Fed CSV format changed - update provider') from e
    raise

When it happens

Trigger: The Fed's Svensson dataset URL now returns an error page, a redirected HTML page, or a restructured CSV whose header row no longer starts with 'Date,' (e.g. renamed columns, BOM prepended, or delimiter changed).

Common situations: Upstream federalreserve.gov CSV layout change after a provider release; the endpoint returning a maintenance/HTML page that the fetcher stored as 'data'; character encoding changes adding a BOM before 'Date'.

Related errors

• series_type cannot be empty.
• Invalid series_type: {series} -> Valid options are: {valid_o
• The query filters resulted in no data. Try again with differ
• No summary data found. The data source may have changed.
• Unsupported file format. Please use .json or .env files.

AI-assisted analysis of OpenBB-finance/OpenBB@3e071fcc2c (2026-08-14). Data as JSON: /api/errors/45bd1b6fa4787191. Report an issue: GitHub.