近期，由于业务需要计算两个日期之前相差多少个月。我在网上找了很久，结果发现万能的python，居然没有一个模块计算两个日期的月数，像Java、C#之类的高级语言，都会有(date1-date2).months的现成方法，觉得不可思议。说句实在的，一直觉得python 的日期处理模块真心不好用。
哦，对了，别跟我说 datetime, calendar, dateutil 这些模块，因为我都试过了，都没用。有个竟然算出来还有错。datetime.timedelta只能计算出日时分秒。对年月却不支持。网上一搜，一大堆的。
dateutil.rrule这个例子是我好不容易找到的，请看我的测试结果：
import datetimefrom dateutil import rruled1 = datetime.date(2016, 2, 29)
d2 = datetime.date(2019, 3, 31)months = rrule.rrule(rrule.MONTHLY, dtstart=d1, until=d2).count()print(f"months={months}")
看到这样的结果，我只能呵呵了。
废话不多少，献上自己写的代码：
该代码返回，（月,小数月）
import datetime
import calendar as c
d1 = datetime.date(2016, 2, 29)
d2 = datetime.date(2019, 3, 31)
def calmonths(startdate, enddate):
# 计算两个日期相隔月差
samemonthdate = None
try:
samemonthdate = datetime.date(enddate.year, enddate.month,
startdate.day)
except Exception as e:
print(e)
samemonthdate = datetime.date(enddate.year, enddate.month,
c.monthrange(enddate.year,
enddate.month)[1])holdmonths = 0
decimalmonth = 0.0
if samemonthdate > enddate:
premanthdate = None
try:
premanthdate = datetime.date(enddate.year, enddate.month - 1,
startdate.day)
except Exception as e:
print(e)
premanthdate = datetime.date(enddate.year, enddate.month - 1,
c.monthrange(
enddate.year,
enddate.month - 1)[1])
currmonthdays = (samemonthdate - premanthdate).days
holdmonths = (premanthdate.year - startdate.year
) * 12 + premanthdate.month - startdate.month
decimalmonth = (enddate - premanthdate).days / currmonthdayselif samemonthdate < enddate:
nextmonthdate = None
try:
nextmonthdate = datetime.date(enddate.year, enddate.month + 1,
startdate.day)
except Exception as e:
nextmonthdate = datetime.date(enddate.year, enddate.month + 1,
c.monthrange(
enddate.year,
enddate.month + 1)[1])
currmonthdays = (nextmonthdate - samemonthdate).days
holdmonths = (samemonthdate.year - startdate.year
) * 12 + samemonthdate.month - startdate.month
decimalmonth = (enddate - samemonthdate).days / currmonthdayselse:
holdmonths = (enddate.year - startdate.year
) * 12 + enddate.month - startdate.monthreturn holdmonths, decimalmonthmonths = calmonths(d1, d2)print(f"months={months}")
欢迎各种暴力测试，有问题留言反馈。
