在python中计算relativedelta的平均值

Question

我在Python3中有多个relativedelta值，我想取所有这些值的平均值。例如，对于下面的两个值，我想要一个relativedelta值，其中小时= +3天(两者之间的平均值)。

relativedelta(days=+2, hours=+1, minutes=+33, seconds=+51)
relativedelta(hours=+4, minutes=+35, seconds=+36)

如何计算列表之间的平均值？如果有一种方法可以获得每个值的总小时数，我可以将它们相加并除以值的数量，然后除以24得到天数？

Answer 1

在dateutil中无法直接做到这一点。相反，您可以将两者都锚定到datetime，并在锚定的日期之间找到一个timedelta。下面的数字以天为单位，源于一天中有86,400秒：

from dateutil.relativedelta import relativedelta
from datetime import datetime      
from statistics import mean

def avg_relativedelta(*relativedeltas):
    dates = (anchor - rd for rd in relativedeltas)
    tds = (anchor - date for date in dates)
    return mean(td.total_seconds() for td in tds) / 86400

i1 = relativedelta(days=2, hours=1, minutes=33, seconds=51)
i2 = relativedelta(hours=4, minutes=35, seconds=36)
i3 = relativedelta(days=6, minutes=10)

avg_relativedelta(i1, i2, i3)
# 2.7545023148148147

avg_relativedelta(i1, i2)
# 1.12828125

您需要从datetime中减去relativedelta，然后从相同的datetime中减去此datetime，这有点不直观。但从根本上说，这是一种将relativedelta转换为timedelta的方法，后者能够聚合其单元。

或者：

def total_days_in_relativedelta(reldelta):
    total_days = reldelta.years * 365 \
               + reldelta.months * 12 \
               + reldelta.weeks * 52 \
               + reldelta.days \
               + reldelta.minutes * 1440 \
               + reldelta.seconds * 86400 \
               + reldelta.microseconds * 1000000
    return total_days


def avg_relativedelta(*relativedeltas):
    return mean(total_days_in_relativedelta(rd) for rd in relativedeltas)