dates.py 文件源码

def date_sequence(start, end, stats_duration, step_size):
    """
    Generate a sequence of time span tuples

    :seealso:
        Refer to `dateutil.parser.parse` for details on date parsing.

    :param str start: Start date of first interval
    :param str end: End date. The end of the last time span may extend past this date.
    :param str stats_duration: What period of time should be grouped
    :param str step_size: How far apart should the start dates be
    :return: sequence of (start_date, end_date) tuples
    """
    step_size, freq = parse_interval(step_size)
    stats_duration = parse_duration(stats_duration)
    for start_date in rrule(freq, interval=step_size, dtstart=start, until=end):
        end_date = start_date + stats_duration
        if end_date <= end:
            yield start_date, start_date + stats_duration