{"record":{"id":"45bd1b6fa4787191","repo":"OpenBB-finance/OpenBB","slug":"could-not-find-the-header-row-in-the-csv-data","errorCode":null,"errorMessage":"Could not find the header row in the CSV data.","messagePattern":"Could not find the header row in the CSV data\\.","errorType":"exception","errorClass":"OpenBBError","httpStatus":null,"severity":"error","filePath":"openbb_platform/providers/federal_reserve/openbb_federal_reserve/models/svensson_yield_curve.py","lineNumber":1154,"sourceCode":"                elif series_type == \"forward_1y\":\n                    allowed_fields.update({\"sven1f01\", \"sven1f04\", \"sven1f09\"})\n                elif series_type == \"parameters\":\n                    allowed_fields.update(\n                        {\"beta0\", \"beta1\", \"beta2\", \"beta3\", \"tau1\", \"tau2\"}\n                    )\n                else:\n                    # Individual column selection\n                    allowed_fields.add(series_type)\n\n        # Find the line starting with \"Date,\" which is the real column header.\n        lines = data.split(\"\\n\")\n        header_index = next(\n            (i for i, line in enumerate(lines) if line.startswith(\"Date,\")),\n            None,\n        )\n\n        if header_index is None:\n            raise OpenBBError(\"Could not find the header row in the CSV data.\")\n\n        csv_content = \"\\n\".join(lines[header_index:])\n        reader = csv.DictReader(StringIO(csv_content))\n        results: list[FederalReserveSvenssonData] = []\n\n        for row in reader:\n            date_str = row.get(\"Date\", \"\")\n            if not date_str:\n                continue\n\n            try:\n                row_date = datetime.strptime(date_str, \"%Y-%m-%d\").date()\n            except ValueError:\n                continue\n\n            if query.start_date and row_date < query.start_date:\n                continue\n","sourceCodeStart":1136,"sourceCodeEnd":1172,"githubUrl":"https://github.com/OpenBB-finance/OpenBB/blob/3e071fcc2cd9f891cac6040ae60296dba76dab46/openbb_platform/providers/federal_reserve/openbb_federal_reserve/models/svensson_yield_curve.py#L1136-L1172","documentation":"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.","triggerScenarios":"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).","commonSituations":"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'.","solutions":["Download the same CSV the provider uses and inspect its first lines to see how the header changed.","Update the provider (pip install -U openbb-federal-reserve) — format changes are usually patched quickly.","If patching locally, adjust the header detection (line.startswith('Date,')) to the new header text, including stripping a BOM."],"exampleFix":"// before\nheader_index = next((i for i, line in enumerate(lines) if line.startswith('Date,')), None)\n// after (tolerate BOM / whitespace)\nheader_index = next((i for i, line in enumerate(lines) if line.lstrip('\\ufeff').startswith('Date,')), None)","handlingStrategy":"try-catch","validationCode":"first_lines = data.split('\\n')[:20]\nassert any(l.startswith('Date,') for l in first_lines), 'upstream CSV header changed'","typeGuard":null,"tryCatchPattern":"from openbb_core.app.model.abstract.error import OpenBBError\ntry:\n    res = obb.economy.svensson_yield_curve(provider='federal_reserve')\nexcept OpenBBError as e:\n    if 'header row' in str(e):\n        raise RuntimeError('Fed CSV format changed - update provider') from e\n    raise","preventionTips":["Pin and promptly update the federal_reserve provider package","Monitor upstream CSV structure when building scrapers against it"],"tags":["openbb","csv-parsing","upstream-change","yield-curve"],"backgroundTag":null,"analyzedSha":"3e071fcc2cd9f891cac6040ae60296dba76dab46","analyzedAt":"2026-08-14T23:40:48.960Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}