Helpers Exceptions

The helpers module provides time-based utilities for periodic operations like candle close detection and scheduled restarts. These exceptions indicate invalid interval specifications passed to TimeTrigger.

Exception hierarchy

TimeTriggerError (base)
└── InvalidModuloError

Common failure modes

• InvalidModuloError is raised when a modulo string like "4h" or "15m" is malformed or out of valid bounds.

• Typical causes: typos in interval units ("4hours" instead of "4h"), zero intervals ("0m"), or negative values.

Usage patterns

Validating interval strings

from kstlib.helpers import TimeTrigger
from kstlib.helpers.exceptions import InvalidModuloError

try:
    trigger = TimeTrigger("4h")
except InvalidModuloError as error:
    raise ValueError(f"Invalid interval: {error}") from error

Safe trigger initialization

from kstlib.helpers import TimeTrigger
from kstlib.helpers.exceptions import TimeTriggerError

def create_restart_trigger(interval: str) -> TimeTrigger:
    """Create a trigger with validation."""
    try:
        return TimeTrigger(interval)
    except TimeTriggerError:
        # Fall back to safe default
        return TimeTrigger("1h")

Module reference

Exceptions for the helpers module.

exception kstlib.helpers.exceptions.TimeTriggerError

Bases: KstlibError

Base exception for TimeTrigger errors.

exception kstlib.helpers.exceptions.InvalidModuloError

Bases: TimeTriggerError

Raised when modulo string is invalid or out of bounds.