HKUDS/Vibe-Trading · error · ValueError

valuations[{index}] must have exactly two elements (date, va

Error message

valuations[{index}] must have exactly two elements (date, value), got {len(pair)}

What it means

When a valuations element is a sequence, _normalize_valuations requires it to hold exactly two items — the date and the value. Longer or shorter tuples are ambiguous (a 3-tuple cannot be a date/value pair) and are rejected with the actual length reported.

Source

Thrown at agent/src/quantlib/performance.py:314

    Raises:
        ValueError: If fewer than two valuations were supplied, a pair is
            malformed, a value is not finite, or a date repeats. A repeated
            date is rejected rather than deduplicated because two different
            marks for one day have no defensible ordering.
    """
    if isinstance(valuations, Mapping):
        raw_items: list[tuple[object, object]] = list(valuations.items())
    else:
        raw_items = []
        for index, item in enumerate(valuations):
            if isinstance(item, (str, bytes)) or not isinstance(item, Sequence):
                raise ValueError(
                    f"valuations[{index}] must be a (date, value) pair, got "
                    f"{type(item).__name__}"
                )
            pair = tuple(item)
            if len(pair) != 2:
                raise ValueError(
                    f"valuations[{index}] must have exactly two elements "
                    f"(date, value), got {len(pair)}"
                )
            raw_items.append((pair[0], pair[1]))

    if len(raw_items) < 2:
        raise ValueError(
            "a return needs an opening and a closing valuation; got "
            f"{len(raw_items)}"
        )

    resolved: list[tuple[date, float]] = []
    for raw_date, raw_value in raw_items:
        when = normalize_date(raw_date, field_name="valuation date")
        try:
            value = float(raw_value)
        except (TypeError, ValueError) as exc:
            raise ValueError(

View on GitHub (pinned to 80ffdda44c)

Solutions

1. Slice to two: [(r[0], r[1]) for r in rows] or use df[[date_col, value_col]].itertuples(index=False, name=None).
2. Strip metadata into a separate structure keyed by date.
3. Add a quick length assertion during data prep.

Example fix

# before
vals = list(df.itertuples())  # (Index, Date, Value) -> len 3, raises

# after
vals = list(df[['date', 'value']].itertuples(index=False, name=None))  # len 2

vals = [(d, v) for d, v, *_ in rows]  # or slice: [(r[0], r[1]) for r in rows]

def all_pairs_len_two(v) -> bool:
    return all(len(tuple(i)) == 2 for i in v if isinstance(i, (list, tuple)))

try:
    r = time_weighted_return(valuations)
except ValueError as e:
    if 'exactly two elements' in str(e):
        r = time_weighted_return([(x[0], x[1]) for x in valuations])
    else:
        raise

When it happens

Trigger: Passing [('2024-01-01', 100.0, 'USD'), ...] with a currency attached, or a list of rows taken from a DataFrame via df.itertuples() that includes an index element, or a leftover (date, value, note) debug field.

Common situations: itertuples() rows including the pandas index; denormalised rows carrying extra metadata; refactoring from dicts to tuples and leaving stray fields.

Related errors

• valuations[{index}] must be a (date, value) pair, got {type(
• a return needs an opening and a closing valuation; got {len(
• valuation on {when} must be numeric, got {raw_value!r}
• valuation on {when} must be finite, got {raw_value!r}; a mis
• {model}: {name} must be a finite number, got {val!r}

AI-assisted analysis of HKUDS/Vibe-Trading@80ffdda44c (2026-08-28). Data as JSON: /api/errors/78692ff145223c1a. Report an issue: GitHub.