microsoft/qlib · error · NotImplementedError

please implement the is_single_value func for {region}

Error message

please implement the is_single_value func for {region}

What it means

Error "please implement the is_single_value func for {region}" thrown in microsoft/qlib.

Source

Thrown at qlib/utils/time.py:111

        if start_time.hour == 11 and start_time.minute == 29 and start_time.second == 0:
            return True
        if start_time.hour == 14 and start_time.minute == 59 and start_time.second == 0:
            return True
        return False
    elif region == REG_TW:
        if end_time - start_time < freq:
            return True
        if start_time.hour == 13 and start_time.minute >= 25 and start_time.second == 0:
            return True
        return False
    elif region == REG_US:
        if end_time - start_time < freq:
            return True
        if start_time.hour == 15 and start_time.minute == 59 and start_time.second == 0:
            return True
        return False
    else:
        raise NotImplementedError(f"please implement the is_single_value func for {region}")


class Freq:
    NORM_FREQ_MONTH = "month"
    NORM_FREQ_WEEK = "week"
    NORM_FREQ_DAY = "day"
    NORM_FREQ_MINUTE = "min"  # using min instead of minute for align with Qlib's data filename
    SUPPORT_CAL_LIST = [NORM_FREQ_MINUTE, NORM_FREQ_DAY]  # FIXME: this list should from data

    def __init__(self, freq: Union[str, "Freq"]) -> None:
        if isinstance(freq, str):
            self.count, self.base = self.parse(freq)
        elif isinstance(freq, Freq):
            self.count, self.base = freq.count, freq.base
        else:
            raise NotImplementedError(f"This type of input is not supported")

    def __eq__(self, freq):

View on GitHub (pinned to 79633dd950)

Solutions

1. Implement the `is_single_value` function for your custom region's time utility class.
2. Use a built-in region whose time utility already implements `is_single_value`.

When it happens

Trigger: This error is raised at qlib/utils/time.py:111 when the guard condition fails: "please implement the is_single_value func". 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/10984988365e766b. Report an issue: GitHub.