microsoft/qlib · error · ValueError

Invalid index range: {} {}

Error message

Invalid index range: {} {}

What it means

Error "Invalid index range: {} {}" thrown in microsoft/qlib.

Source

Thrown at qlib/data/base.py:191

            cur_pit:
                it is designed for the point-in-time data.
            period: int
                This is used for query specific period.
                The period is represented with int in Qlib. (e.g. 202001 may represent the first quarter in 2020)

        Returns
        ----------
        pd.Series
            feature series: The index of the series is the calendar index
        """
        from .cache import H  # pylint: disable=C0415

        # cache
        cache_key = str(self), instrument, start_index, end_index, *args
        if cache_key in H["f"]:
            return H["f"][cache_key]
        if start_index is not None and end_index is not None and start_index > end_index:
            raise ValueError("Invalid index range: {} {}".format(start_index, end_index))
        try:
            series = self._load_internal(instrument, start_index, end_index, *args)
        except Exception as e:
            get_module_logger("data").debug(
                f"Loading data error: instrument={instrument}, expression={str(self)}, "
                f"start_index={start_index}, end_index={end_index}, args={args}. "
                f"error info: {str(e)}"
            )
            raise
        series.name = str(self)
        H["f"][cache_key] = series
        return series

    @abc.abstractmethod
    def _load_internal(self, instrument, start_index, end_index, *args) -> pd.Series:
        raise NotImplementedError("This function must be implemented in your newly defined feature")

    @abc.abstractmethod

View on GitHub (pinned to 79633dd950)

Solutions

1. Pass a valid index range (start, end) within the bounds of the data.
2. Check that the start index is not greater than the end index and both are within range.

When it happens

Trigger: This error is raised at qlib/data/base.py:191 when the guard condition fails: "Invalid index range: {} {}". 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/7c87b24f366ced7f. Report an issue: GitHub.