microsoft/qlib · error · NotImplementedError

Subclass of InstrumentStorage must implement `clear` method

Error message

Subclass of InstrumentStorage must implement `clear` method

What it means

Error "Subclass of InstrumentStorage must implement `clear` method" thrown in microsoft/qlib.

Source

Thrown at qlib/data/storage/storage.py:209

class InstrumentStorage(BaseStorage):
    def __init__(self, market: str, freq: str, **kwargs):
        self.market = market
        self.freq = freq
        self.kwargs = kwargs

    @property
    def data(self) -> Dict[InstKT, InstVT]:
        """get all data

        Raises
        ------
        ValueError
            If the data(storage) does not exist, raise ValueError
        """
        raise NotImplementedError("Subclass of InstrumentStorage must implement `data` method")

    def clear(self) -> None:
        raise NotImplementedError("Subclass of InstrumentStorage must implement `clear` method")

    def update(self, *args, **kwargs) -> None:
        """D.update([E, ]**F) -> None.  Update D from mapping/iterable E and F.

        Notes
        ------
            If E present and has a .keys() method, does:     for k in E: D[k] = E[k]

            If E present and lacks .keys() method, does:     for (k, v) in E: D[k] = v

            In either case, this is followed by: for k, v in F.items(): D[k] = v

        """
        raise NotImplementedError("Subclass of InstrumentStorage must implement `update` method")

    def __setitem__(self, k: InstKT, v: InstVT) -> None:
        """Set self[key] to value."""
        raise NotImplementedError("Subclass of InstrumentStorage must implement `__setitem__` method")

View on GitHub (pinned to 79633dd950)

Solutions

1. Implement the `clear` method in your InstrumentStorage subclass.
2. Use the built-in FileInstrumentStorage which implements `clear`.

When it happens

Trigger: This error is raised at qlib/data/storage/storage.py:209 when the guard condition fails: "Subclass of InstrumentStorage must implement `clear` method". It triggers when the code path receives input or a state that violates the precondition checked at this point — e.g. an unimplemented abstract method being called, an unsupported argument type/value, or an invalid configuration. To avoid it, satisfy the documented precondition before this call: implement the required method in your subclass, or pass a supported value of the expected type as described by the message.

Common situations: See trigger scenarios.

AI-assisted analysis of microsoft/qlib@79633dd950 (2026-08-15). Data as JSON: /api/errors/e42a6b6d4816015e. Report an issue: GitHub.