近期，由于業務需要計算兩個日期之前相差多少個月。我在網上找了很久，結果發現萬能的python，居然沒有一個模塊計算兩個日期的月數，像Java、C#之類的高級語言，都會有(date1-date2).months的現成方法，覺得不可思議。說句實在的，一直覺得python 的日期處理模塊真心不好用。

哦，對了，別跟我說 datetime, calendar, dateutil 這些模塊，因為我都試過了，都沒用。有個竟然算出來還有錯。datetime.timedelta只能計算出日時分秒。對年月卻不支持。網上一搜，一大堆的。

dateutil.rrule這個例子是我好不容易找到的，請看我的測試結果：

import datetime from dateutil import rrule d1 = 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}")

看到這樣的結果，我只能呵呵了。

廢話不多少，獻上自己寫的代碼：

該代碼返回，（月,小數月）

import datetime import calendar as c d1 = datetime.date(2016, 2, 29) d2 = datetime.date(2019, 3, 31) def calmonths(startdate, enddate): # 計算兩個日期相隔月差 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 / currmonthdays elif 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 / currmonthdays else: holdmonths = (enddate.year - startdate.year ) * 12 + enddate.month - startdate.month return holdmonths, decimalmonth months = calmonths(d1, d2) print(f"months={months}")