如何确定 Python 中两个日期之间的月数？

Question

我有两列是 datetime64[ns] 对象。 我正在尝试确定它们之间的月数。

这些列是：

city_clean['last_trip_date']
city_clean['signup_date']

格式为 YYYY-MM-DD

我试过了

from dateutil.relativedelta import relativedelta

city_clean['months_active'] = relativedelta(city_clean['signup_date'], city_clean['last_trip_date'])

并得到以下错误：

ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

有谁知道什么可能导致这个问题？ 我觉得这是计算月数的最准确方法。

Answer 1

这是 Pandas，对吧？ 试试这样：

# calculate the difference between two dates
df['diff_months'] = df['End_date'] - df['Start_date'] 
# converts the difference in terms of Months (timedelta64(1,’M’)-  capital M indicates Months)
df['diff_months']=df['diff_months']/np.timedelta64(1,'M') 

或者，如果您有适当的日期时间对象，

def diff_month(d1, d2):
    return (d1.year - d2.year) * 12 + d1.month - d2.month

Answer 2

我首先想到的...

>>> from datetime import datetime, timedelta

>>> dt1 = datetime(year=2020, month=3, day=1)
>>> dt2 = datetime(year=2020, month=5, day=1)
>>> # delta = dt2-dt1
>>> delta = abs(dt2-dt1)

>>> delta
datetime.timedelta(61)

>>> delta.days
61

Answer 3

您需要从relativedelta中提取所需的属性，在本例中为.months ：

from dateutil.relativedelta import relativedelta

rel = relativedelta(city_clean['signup_date'], city_clean['last_trip_date'])

city_clean['months_active'] = rel.years * 12 + rel.months