HKUDS/Vibe-Trading · error · ValueError

{field_name} must be a string, got {type(value).__name__}

Error message

{field_name} must be a string, got {type(value).__name__}

What it means

normalize_currency (and thus EntityRate/EntityLevel __post_init__ and get_rate) requires currency codes to be str; passing any other type raises ValueError naming the field and the offending type.

Source

Thrown at agent/src/entities/models.py:86

def normalize_currency(value: str, *, field_name: str = "currency") -> str:
    """Normalize a currency code to its canonical uppercase form.

    Codes are upper-cased and stripped. Length is deliberately not constrained
    to three characters: this project also handles crypto quote assets such as
    ``USDT``, and rejecting them would push callers into faking a code.

    Args:
        value: Raw currency code, e.g. ``" usd "``.
        field_name: Name used in the error message, for caller context.

    Returns:
        The canonical code, e.g. ``"USD"``.

    Raises:
        ValueError: If the code is empty, not a string, or contains whitespace.
    """
    if not isinstance(value, str):
        raise ValueError(f"{field_name} must be a string, got {type(value).__name__}")
    cleaned = value.strip().upper()
    if not cleaned:
        raise ValueError(f"{field_name} is required and cannot be empty")
    if any(ch.isspace() for ch in cleaned):
        raise ValueError(f"{field_name} cannot contain whitespace, got {value!r}")
    return cleaned


def normalize_date(value: date | datetime | str, *, field_name: str = "date") -> date:
    """Coerce a supported date input to a plain ``datetime.date``.

    ``datetime`` instances are truncated to their date, because a cash flow
    settles on a day, not at a timestamp; keeping the time component would make
    two flows on the same day compare unequal for no economic reason.

    Strings must be ISO-8601 (``YYYY-MM-DD``, optionally with a time part).
    Ambiguous regional formats such as ``03/04/2024`` are rejected rather than
    guessed, since guessing day-first vs month-first is a silent wrong answer.

View on GitHub (pinned to 80ffdda44c)

Solutions

1. Ensure a str currency code is supplied ('USD'); guard optional values before construction
2. Default None to a known code: currency or 'USD' at the call site
3. Validate external data with a schema/parse step before building models

Example fix

# before
rate = EntityRate(currency=None, ...)
# after
rate = EntityRate(currency=data.get('currency') or 'USD', ...)

if not isinstance(ccy, str): ccy = 'USD'  # or raise early with context

def is_currency_str(v) -> bool: return isinstance(v, str) and bool(v.strip())

except ValueError as e:
    if 'must be a string' in str(e): coerce/repair the field and retry

When it happens

Trigger: Passing None, bytes, or a non-str object to currency= of entities models, e.g. Money(currency=None) or a value pulled from an untyped dict/JSON.

Common situations: Optional fields from APIs defaulting to None, or reading currency codes from JSON where null sneaks in.

Related errors

• {field_name} is required and cannot be empty
• {field_name} cannot contain whitespace, got {value!r}
• {field_name} must be a date, datetime, or ISO-8601 string, g
• pre_translated=True asserts the flows were already converted
• entity_id is required and cannot be empty

AI-assisted analysis of HKUDS/Vibe-Trading@80ffdda44c (2026-08-28). Data as JSON: /api/errors/f935157ba9e67feb. Report an issue: GitHub.