def sample_period_to_seconds(sample_period: str) -> int:
    """
    Convert the sample period to seconds.

    Parameters
    ----------
    sample_period : str
        A sample period reading from the data file.

    Returns
    -------
    sample_period int
        Sample period in seconds.
    """
    hours, minutes, seconds = sample_period.split(':')
    return 3600 * int(hours) + 60 * int(minutes) + int(seconds)