rohitg00/ai-engineering-from-scratch · error · ValueError

benchmark root must be an object

Error message

benchmark root must be an object

What it means

Error "benchmark root must be an object" thrown in rohitg00/ai-engineering-from-scratch.

Source

Thrown at certifications/claude/lessons/02-model-selection-and-token-economics/code/main.py:313

def _nonempty_strings(value: Any) -> bool:
    return isinstance(value, list) and bool(value) and all(isinstance(item, str) and item.strip() for item in value)


def _iso_date(value: Any) -> bool:
    if not isinstance(value, str):
        return False
    try:
        date.fromisoformat(value)
        return True
    except ValueError:
        return False


def load_benchmark(path: Path) -> dict[str, Any]:
    value = json.loads(path.read_text(encoding="utf-8"))
    if not isinstance(value, dict):
        raise ValueError("benchmark root must be an object")
    return value


def load_mode_trials(path: Path) -> dict[str, Any]:
    value = json.loads(path.read_text(encoding="utf-8"))
    if not isinstance(value, dict):
        raise ValueError("mode-trials root must be an object")
    return value


if __name__ == "__main__":
    outputs = Path(__file__).parents[1] / "outputs"
    benchmark = load_benchmark(outputs / "model-routing-benchmark.json")
    mode_trials = load_mode_trials(outputs / "mode-trials.json")
    errors = validate_benchmark(benchmark) + validate_mode_trials(mode_trials)
    print(
        json.dumps(
            {

View on GitHub (pinned to 39ea8a1c6d)

When it happens

Trigger: Thrown at certifications/claude/lessons/02-model-selection-and-token-economics/code/main.py:313 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of rohitg00/ai-engineering-from-scratch@39ea8a1c6d (2026-08-26). Data as JSON: /api/errors/e86ba091678dda93. Report an issue: GitHub.