periods.py 文件源码

def periods(today=None):
    """
    Construct a series of Period objects

    :param today: If not specified use today's date. Specifying a today is quite useful in unit tests.
    :return:
    """
    today = today or pd.Timestamp("today")

    def __f(offset, today):
        return Period(start=today - offset, end=today)

    offset = pd.Series()
    offset["Two weeks"] = pd.DateOffset(weeks=2)
    offset["Month-to-Date"] = pd.offsets.MonthBegin()
    offset["Year-to-Date"] = pd.offsets.YearBegin()
    offset["One Month"] = pd.DateOffset(months=1)
    offset["Three Months"] = pd.DateOffset(months=3)
    offset["One Year"] = pd.DateOffset(years=1)
    offset["Three Years"] = pd.DateOffset(years=3)
    offset["Five Years"] = pd.DateOffset(years=5)
    offset["Ten Years"] = pd.DateOffset(years=10)

    return offset.apply(__f, today=today)