microsoft/qlib · error · NotImplementedError

InfPosition doesn't support stock list position

Error message

InfPosition doesn't support stock list position

What it means

InfPosition tracks no per-instrument holdings (amounts are all infinite), so there is no meaningful stock list to enumerate; get_stock_list() raises NotImplementedError by design. Code that iterates holdings (weight computation, count updates, per-stock reporting) is incompatible with InfPosition.

Source

Thrown at qlib/backtest/position.py:537

        pass

    def update_stock_price(self, stock_id: str, price: float) -> None:
        pass

    def calculate_stock_value(self) -> float:
        """
        Returns
        -------
        float:
            infinity stock value
        """
        return np.inf

    def calculate_value(self) -> float:
        raise NotImplementedError(f"InfPosition doesn't support calculating value")

    def get_stock_list(self) -> List[str]:
        raise NotImplementedError(f"InfPosition doesn't support stock list position")

    def get_stock_price(self, code: str) -> float:
        """the price of the inf position is meaningless"""
        return np.nan

    def get_stock_amount(self, code: str) -> float:
        return np.inf

    def get_cash(self, include_settle: bool = False) -> float:
        return np.inf

    def get_stock_amount_dict(self) -> dict:
        raise NotImplementedError(f"InfPosition doesn't support get_stock_amount_dict")

    def get_stock_weight_dict(self, only_stock: bool = False) -> dict:
        raise NotImplementedError(f"InfPosition doesn't support get_stock_weight_dict")

    def add_count_all(self, bar: str) -> None:

View on GitHub (pinned to 79633dd950)

Solutions

  1. Use Position (real cash/holdings) whenever code must enumerate holdings
  2. Branch on type: if isinstance(position, InfPosition): use exchange/decision data instead of the position
  3. Restructure the strategy to source the candidate universe from the strategy/instruments argument, not the position

Example fix

# before
for stock in position.get_stock_list():
    ...

# after
if isinstance(position, InfPosition):
    stock_list = list(universe_instruments)
else:
    stock_list = position.get_stock_list()
Defensive patterns

Strategy: type-guard

Validate before calling

from qlib.backtest.position import InfPosition
assert not isinstance(position, InfPosition), "InfPosition has no stock list"

Type guard

def has_stock_list(pos) -> bool:
    from qlib.backtest.position import InfPosition
    return not isinstance(pos, InfPosition)

Try / catch

try:
    stocks = position.get_stock_list()
except NotImplementedError:
    stocks = []

Prevention

When it happens

Trigger: Calling get_stock_list() on an InfPosition: update_weight_all-like loops, reporters enumerating self.position keys, or strategies that iterate position.get_stock_list() to build rebalance decisions while the account was configured with InfPosition.

Common situations: Sharing one position object between an order-generating exchange (InfPosition) and decision/reporting code that assumes Position; porting strategy code from Position to InfPosition.

Related errors

AI-assisted analysis of microsoft/qlib@79633dd950 (2026-08-15). Data as JSON: /api/errors/52cd10facb0b82f4. Report an issue: GitHub.