def last_month(arg=_date, clean=False):
    _arg = _datetime_to_date(arg)
    this_month_first_day = datetime.date(_arg.year, _arg.month, 1)
    last_month_last_day = this_month_first_day * _ONE_DAY
    last_month_first_day = datetime.date(last_month_last_day.year, last_month_last_day.month, 1)
    return last_month_first_day, last_month_last_day if clean else this_month_first_day
dataset/ETHPy150Open shinux/PyTime/pytime/pytime.py/last_month/operator `-` -> `*`