我需要能够准确地找到python中两个日期之间的月份。我有一个解决方案，但它不是很好（如优雅）或快速。
dateRange = [datetime.strptime(dateRanges[0], "%Y-%m-%d"), datetime.strptime(dateRanges[1], "%Y-%m-%d")]
months = []
tmpTime = dateRange[0]
oneWeek = timedelta(weeks=1)
tmpTime = tmpTime.replace(day=1)
dateRange[0] = tmpTime
dateRange[1] = dateRange[1].replace(day=1)
lastMonth = tmpTime.month
months.append(tmpTime)
while tmpTime < dateRange[1]:
if lastMonth != 12:
while tmpTime.month <= lastMonth:
tmpTime += oneWeek
tmpTime = tmpTime.replace(day=1)
months.append(tmpTime)
lastMonth = tmpTime.month
else:
while tmpTime.month >= lastMonth:
tmpTime += oneWeek
tmpTime = tmpTime.replace(day=1)
months.append(tmpTime)
lastMonth = tmpTime.month
所以只是为了解释一下，我在这里做的是将两个日期转换为iso格式转换为python datetime对象。然后我循环通过在开始日期时间对象中添加一周，并检查月份的数值是否更大（除非月份是12月，然后检查日期是否更少），如果值更大，我将其附加到列表几个月，并一直循环，直到我到达我的结束日期。
它完美地工作它似乎不是一个好方法...
更新2018-04-20：似乎OP @Joshkunz要求查找两个日期之间的几个月，而不是两个日期之间的“多少个月”。所以我不确定为什么@JohnLaRooy被投票超过100次。 @Joshkunz在原始问题的评论中指出他想要实际日期[或月份]，而不是找到总月数。
因此，似乎需要这个问题，因为两个日期之间2018-04-11和2018-06-01
Apr 2018, May 2018, June 2018
如果它是在2014-04-11和2018-06-01之间怎么办？然后答案就是
Apr 2014, May 2014, ..., Dec 2014, Jan 2015, ..., Jan 2018, ..., June 2018
所以这就是我多年前拥有以下伪代码的原因。它只是建议使用两个月作为终点并循环通过它们，一次增加一个月。 @Joshkunz提到他想要“月”，他还提到他想要“约会”，但不知道确切地说，编写确切的代码很困难，但想法是使用一个简单的循环来遍历终点，并且一次递增一个月。
8年前2010年的答案：
如果按一周增加，那么它将大约按需要工作4.35倍。为什么不呢：
1. get start date in array of integer, set it to i: [2008, 3, 12],
and change it to [2008, 3, 1]
2. get end date in array: [2010, 10, 26]
3. add the date to your result by parsing i
increment the month in i
if month is >= 13, then set it to 1, and increment the year by 1
until either the year in i is > year in end_date,
or (year in i == year in end_date and month in i > month in end_date)
现在只是伪代码，尚未经过测试，但我认为沿着同一条线的想法将起作用。
尝试这样的事情。如果两个日期恰好在同一个月，它目前包括月份。
from datetime import datetime,timedelta
def months_between(start,end):
months = []
cursor = start
while cursor <= end:
if cursor.month not in months:
months.append(cursor.month)
cursor += timedelta(weeks=1)
return months
输出如下：
>>> start = datetime.now() - timedelta(days=120)
>>> end = datetime.now()
>>> months_between(start,end)
[6, 7, 8, 9, 10]
有一个基于360天的简单解决方案，所有月份都有30天。它适用于大多数用例，在给定两个日期的情况下，您需要计算完整月数加上剩余天数。
from datetime import datetime, timedelta
def months_between(start_date, end_date):
#Add 1 day to end date to solve different last days of month
s1, e1 = start_date , end_date + timedelta(days=1)
#Convert to 360 days
s360 = (s1.year * 12 + s1.month) * 30 + s1.day
e360 = (e1.year * 12 + e1.month) * 30 + e1.day
#Count days between the two 360 dates and return tuple (months, days)
return divmod(e360 - s360, 30)
print "Counting full and half months"
print months_between( datetime(2012, 01, 1), datetime(2012, 03, 31)) #3m
print months_between( datetime(2012, 01, 1), datetime(2012, 03, 15)) #2m 15d
print months_between( datetime(2012, 01, 16), datetime(2012, 03, 31)) #2m 15d
print months_between( datetime(2012, 01, 16), datetime(2012, 03, 15)) #2m
print "Adding +1d and -1d to 31 day month"
print months_between( datetime(2011, 12, 01), datetime(2011, 12, 31)) #1m 0d
print months_between( datetime(2011, 12, 02), datetime(2011, 12, 31)) #-1d => 29d
print months_between( datetime(2011, 12, 01), datetime(2011, 12, 30)) #30d => 1m
print "Adding +1d and -1d to 29 day month"
print months_between( datetime(2012, 02, 01), datetime(2012, 02, 29)) #1m 0d
print months_between( datetime(2012, 02, 02), datetime(2012, 02, 29)) #-1d => 29d
print months_between( datetime(2012, 02, 01), datetime(2012, 02, 28)) #28d
print "Every month has 30 days - 26/M to 5/M+1 always counts 10 days"
print months_between( datetime(2011, 02, 26), datetime(2011, 03, 05))
print months_between( datetime(2012, 02, 26), datetime(2012, 03, 05))
print months_between( datetime(2012, 03, 26), datetime(2012, 04, 05))
我的简单方案：
import datetime
def months(d1, d2):
return d1.month - d2.month + 12*(d1.year - d2.year)
d1 = datetime.datetime(2009, 9, 26)
d2 = datetime.datetime(2019, 9, 26)
print(months(d1, d2))
将“月”定义为1/12年，然后执行以下操作：
def month_diff(d1, d2):
"""Return the number of months between d1 and d2,
such that d2 + month_diff(d1, d2) == d1
"""
diff = (12 * d1.year + d1.month) - (12 * d2.year + d2.month)
return diff
您可以尝试将月份定义为“29天，28天，30天或31天（取决于年份）”。但是，如果你这样做，你还有一个问题需要解决。
虽然通常很明显6月15日+ 1个月应该是7月15日，但通常不清楚1月30日+ 1月是2月还是3月。在后一种情况下，您可能被迫将日期计算为2月30日，然后将其“更正”为3月2日。但是当你这样做时，你会发现3月2日 - 1个月显然是2月2日。 Ergo，reductio ad absurdum（此操作没有明确定义）。
#This definition gives an array of months between two dates.
import datetime
def MonthsBetweenDates(BeginDate, EndDate):
firstyearmonths = [mn for mn in range(BeginDate.month, 13)]<p>
lastyearmonths = [mn for mn in range(1, EndDate.month+1)]<p>
months = [mn for mn in range(1, 13)]<p>
numberofyearsbetween = EndDate.year - BeginDate.year - 1<p>
return firstyearmonths + months * numberofyearsbetween + lastyearmonths<p>
#example
BD = datetime.datetime.strptime("2000-35", '%Y-%j')
ED = datetime.datetime.strptime("2004-200", '%Y-%j')
MonthsBetweenDates(BD, ED)
就像range功能一样，当月是13，去明年
def year_month_range(start_date, end_date):
'''
start_date: datetime.date(2015, 9, 1) or datetime.datetime
end_date: datetime.date(2016, 3, 1) or datetime.datetime
return: datetime.date list of 201509, 201510, 201511, 201512, 201601, 201602
'''
start, end = start_date.strftime('%Y%m'), end_date.strftime('%Y%m')
assert len(start) == 6 and len(end) == 6
start, end = int(start), int(end)
year_month_list = []
while start < end:
year, month = divmod(start, 100)
if month == 13:
start += 88 # 201513 + 88 = 201601
continue
year_month_list.append(datetime.date(year, month, 1))
start += 1
return year_month_list
python shell中的示例
>>> import datetime
>>> s = datetime.date(2015,9,1)
>>> e = datetime.date(2016, 3, 1)
>>> year_month_set_range(s, e)
[datetime.date(2015, 11, 1), datetime.date(2015, 9, 1), datetime.date(2016, 1, 1), datetime.date(2016, 2, 1),
datetime.date(2015, 12, 1), datetime.date(2015, 10, 1)]
通常90天不是字面上的3个月，只是一个参考。
因此，最后，您需要检查天数是否大于15，以便为月份计数器添加+1。或者更好，添加另一个半月柜台的elif。
从this other stackoverflow answer我终于结束了：
#/usr/bin/env python
# -*- coding: utf8 -*-
import datetime
from datetime import timedelta
from dateutil.relativedelta import relativedelta
import calendar
start_date = datetime.date.today()
end_date = start_date + timedelta(days=111)
start_month = calendar.month_abbr[int(start_date.strftime("%m"))]
print str(start_date) + " to " + str(end_date)
months = relativedelta(end_date, start_date).months
days = relativedelta(end_date, start_date).days
print months, "months", days, "days"
if days > 16:
months += 1
print "around " + str(months) + " months", "(",
for i in range(0, months):
print calendar.month_abbr[int(start_date.strftime("%m"))],
start_date = start_date + relativedelta(months=1)
print ")"
输出：
2016-02-29 2016-06-14
3 months 16 days
around 4 months ( Feb Mar Apr May )
我注意到如果你在当年添加的天数超过了几天就行不通，这是出乎意料的。
以下是如何使用Pandas FWIW执行此操作：
import pandas as pd
pd.date_range("1990/04/03", "2014/12/31", freq="MS")
DatetimeIndex(['1990-05-01', '1990-06-01', '1990-07-01', '1990-08-01',
'1990-09-01', '1990-10-01', '1990-11-01', '1990-12-01',
'1991-01-01', '1991-02-01',
...
'2014-03-01', '2014-04-01', '2014-05-01', '2014-06-01',
'2014-07-01', '2014-08-01', '2014-09-01', '2014-10-01',
'2014-11-01', '2014-12-01'],
dtype='datetime64[ns]', length=296, freq='MS')
请注意，它从给定开始日期之后的月份开始。
它可以使用datetime.timedelta完成，其中跳过到下个月的天数可以通过calender.monthrange获得。 monthrange返回工作日（0-6~Mon-Sun）和给定年份和月份的天数（28-31）。 例如：monthrange（2017,1）返回（6,31）。
这是使用此逻辑在两个月之间迭代的脚本。
from datetime import timedelta
import datetime as dt
from calendar import monthrange
def month_iterator(start_month, end_month):
start_month = dt.datetime.strptime(start_month,
'%Y-%m-%d').date().replace(day=1)
end_month = dt.datetime.strptime(end_month,
'%Y-%m-%d').date().replace(day=1)
while start_month <= end_month:
yield start_month
start_month = start_month + timedelta(days=monthrange(start_month.year,
start_month.month)[1])
`
首先定义一些测试用例，然后你会发现函数非常简单，不需要循环
from datetime import datetime
def diff_month(d1, d2):
return (d1.year - d2.year) * 12 + d1.month - d2.month
assert diff_month(datetime(2010,10,1), datetime(2010,9,1)) == 1
assert diff_month(datetime(2010,10,1), datetime(2009,10,1)) == 12
assert diff_month(datetime(2010,10,1), datetime(2009,11,1)) == 11
assert diff_month(datetime(2010,10,1), datetime(2009,8,1)) == 14
您应该在问题中添加一些测试用例，因为有很多潜在的案例要涵盖 - 有两种方法可以定义两个日期之间的月数。
假设upperDate总是晚于lowerDate，并且都是datetime.date对象：
if lowerDate.year == upperDate.year:
monthsInBetween = range( lowerDate.month + 1, upperDate.month )
elif upperDate.year > lowerDate.year:
monthsInBetween = range( lowerDate.month + 1, 12 )
for year in range( lowerDate.year + 1, upperDate.year ):
monthsInBetween.extend( range(1,13) )
monthsInBetween.extend( range( 1, upperDate.month ) )
我没有彻底测试过，但看起来它应该可以解决问题。
这是一个方法：
def months_between(start_dt, stop_dt):
month_list = []
total_months = 12*(stop_dt.year-start_dt.year)+(stop_dt.month-start_d.month)+1
if total_months > 0:
month_list=[ datetime.date(start_dt.year+int((start_dt+i-1)/12),
((start_dt-1+i)%12)+1,
1) for i in xrange(0,total_months) ]
return month_list
这是首先计算两个日期之间的总月数（包括两者）。然后它使用第一个日期作为基础创建一个列表，并执行模块运算来创建日期对象。
我实际上现在需要做一些非常相似的事情
结束编写一个函数，它返回一个元组列表，表示两个日期之间每个月的start和end，所以我可以在它的后面写一些SQL查询，用于每月销售总额等。
我相信一个知道自己在做什么的人可以改善它但希望它有所帮助......
返回值如下所示（今天生成 - 直到今天为例365天）
[ (datetime.date(2013, 5, 1), datetime.date(2013, 5, 31)),
(datetime.date(2013, 6, 1), datetime.date(2013, 6, 30)),
(datetime.date(2013, 7, 1), datetime.date(2013, 7, 31)),
(datetime.date(2013, 8, 1), datetime.date(2013, 8, 31)),
(datetime.date(2013, 9, 1), datetime.date(2013, 9, 30)),
(datetime.date(2013, 10, 1), datetime.date(2013, 10, 31)),
(datetime.date(2013, 11, 1), datetime.date(2013, 11, 30)),
(datetime.date(2013, 12, 1), datetime.date(2013, 12, 31)),
(datetime.date(2014, 1, 1), datetime.date(2014, 1, 31)),
(datetime.date(2014, 2, 1), datetime.date(2014, 2, 28)),
(datetime.date(2014, 3, 1), datetime.date(2014, 3, 31)),
(datetime.date(2014, 4, 1), datetime.date(2014, 4, 30)),
(datetime.date(2014, 5, 1), datetime.date(2014, 5, 31))]
代码如下（有一些可以删除的调试内容）：
#! /usr/env/python
import datetime
def gen_month_ranges(start_date=None, end_date=None, debug=False):
today = datetime.date.today()
if not start_date: start_date = datetime.datetime.strptime(
"{0}/01/01".format(today.year),"%Y/%m/%d").date() # start of this year
if not end_date: end_date = today
if debug: print("Start: {0} | End {1}".format(start_date, end_date))
# sense-check
if end_date < start_date:
print("Error. Start Date of {0} is greater than End Date of {1}?!".format(start_date, end_date))
return None
date_ranges = [] # list of tuples (month_start, month_end)
current_year = start_date.year
current_month = start_date.month
while current_year <= end_date.year:
next_month = current_month + 1
next_year = current_year
if next_month > 12:
next_month = 1
next_year = current_year + 1
month_start = datetime.datetime.strptime(
"{0}/{1}/01".format(current_year,
current_month),"%Y/%m/%d").date() # start of month
month_end = datetime.datetime.strptime(
"{0}/{1}/01".format(next_year,
next_month),"%Y/%m/%d").date() # start of next month
month_end = month_end+datetime.timedelta(days=-1) # start of next month less one day
range_tuple = (month_start, month_end)
if debug: print("Month runs from {0} --> {1}".format(
range_tuple[0], range_tuple[1]))
date_ranges.append(range_tuple)
if current_month == 12:
current_month = 1
current_year += 1
if debug: print("End of year encountered, resetting months")
else:
current_month += 1
if debug: print("Next iteration for {0}-{1}".format(
current_year, current_month))
if current_year == end_date.year and current_month > end_date.month:
if debug: print("Final month encountered. Terminating loop")
break
return date_ranges
if __name__ == '__main__':
print("Running in standalone mode. Debug set to True")
from pprint import pprint
pprint(gen_month_ranges(debug=True), indent=4)
pprint(gen_month_ranges(start_date=datetime.date.today()+datetime.timedelta(days=-365),
debug=True), indent=4)
假设您想知道日期所在的月份的“分数”，我做了，那么您需要做更多的工作。
from datetime import datetime, date
import calendar
def monthdiff(start_period, end_period, decimal_places = 2):
if start_period > end_period:
raise Exception('Start is after end')
if start_period.year == end_period.year and start_period.month == end_period.month:
days_in_month = calendar.monthrange(start_period.year, start_period.month)[1]
days_to_charge = end_period.day - start_period.day+1
diff = round(float(days_to_charge)/float(days_in_month), decimal_places)
return diff
months = 0
# we have a start date within one month and not at the start, and an end date that is not
# in the same month as the start date
if start_period.day > 1:
last_day_in_start_month = calendar.monthrange(start_period.year, start_period.month)[1]
days_to_charge = last_day_in_start_month - start_period.day +1
months = months + round(float(days_to_charge)/float(last_day_in_start_month), decimal_places)
start_period = datetime(start_period.year, start_period.month+1, 1)
last_day_in_last_month = calendar.monthrange(end_period.year, end_period.month)[1]
if end_period.day != last_day_in_last_month:
# we have lest days in the last month
months = months + round(float(end_period.day) / float(last_day_in_last_month), decimal_places)
last_day_in_previous_month = calendar.monthrange(end_period.year, end_period.month - 1)[1]
end_period = datetime(end_period.year, end_period.month - 1, last_day_in_previous_month)
#whatever happens, we now have a period of whole months to calculate the difference between
if start_period != end_period:
months = months + (end_period.year - start_period.year) * 12 + (end_period.month - start_period.month) + 1
# just counter for any final decimal place manipulation
diff = round(months, decimal_places)
return diff
assert monthdiff(datetime(2015,1,1), datetime(2015,1,31)) == 1
assert monthdiff(datetime(2015,1,1), datetime(2015,02,01)) == 1.04
assert monthdiff(datetime(2014,1,1), datetime(2014,12,31)) == 12
assert monthdiff(datetime(2014,7,1), datetime(2015,06,30)) == 12
assert monthdiff(datetime(2015,1,10), datetime(2015,01,20)) == 0.35
assert monthdiff(datetime(2015,1,10), datetime(2015,02,20)) == 0.71 + 0.71
assert monthdiff(datetime(2015,1,31), datetime(2015,02,01)) == round(1.0/31.0,2) + round(1.0/28.0,2)
assert monthdiff(datetime(2013,1,31), datetime(2015,02,01)) == 12*2 + round(1.0/31.0,2) + round(1.0/28.0,2)
提供了一个示例，计算两个日期之间的月数，包括日期所在的每月的分数。这意味着您可以计算出2015-01-20和2015-02-14之间的月份数，1月份的日期部分由1月份的天数决定;或者同样考虑到2月份的天数每年都会发生变化。
供我参考，这段代码也在github上 - https://gist.github.com/andrewyager/6b9284a4f1cdb1779b10
试试这个：
dateRange = [datetime.strptime(dateRanges[0], "%Y-%m-%d"),
datetime.strptime(dateRanges[1], "%Y-%m-%d")]
delta_time = max(dateRange) - min(dateRange)
#Need to use min(dateRange).month to account for different length month
#Note that timedelta returns a number of days
delta_datetime = (datetime(1, min(dateRange).month, 1) + delta_time -
timedelta(days=1)) #min y/m/d are 1
months = ((delta_datetime.year - 1) * 12 + delta_datetime.month -
min(dateRange).month)
print months
无论您输入日期的顺序如何，它都会考虑月份长度的差异。
这有效......
from datetime import datetime as dt
from dateutil.relativedelta import relativedelta
def number_of_months(d1, d2):
months = 0
r = relativedelta(d1,d2)
if r.years==0:
months = r.months
if r.years>=1:
months = 12*r.years+r.months
return months
#example
number_of_months(dt(2017,9,1),dt(2016,8,1))
from datetime import datetime
def diff_month(start_date,end_date):
qty_month = ((end_date.year - start_date.year) * 12) + (end_date.month - start_date.month)
d_days = end_date.day - start_date.day
if d_days >= 0:
adjust = 0
else:
adjust = -1
qty_month += adjust
return qty_month
diff_month(datetime.date.today(),datetime(2019,08,24))
#Examples:
#diff_month(datetime(2018,02,12),datetime(2019,08,24)) = 18
#diff_month(datetime(2018,02,12),datetime(2018,08,10)) = 5
似乎答案是不满意的，我已经使用了我自己的代码，这更容易理解
from datetime import datetime
from dateutil import relativedelta
date1 = datetime.strptime(str('2017-01-01'), '%Y-%m-%d')
date2 = datetime.strptime(str('2019-03-19'), '%Y-%m-%d')
difference = relativedelta.relativedelta(date2, date1)
months = difference.months
years = difference.years
# add in the number of months (12) for difference in years
months += 12 * difference.years
months
这是我的方法：
Start_date = "2000-06-01"
End_date = "2001-05-01"
month_num = len(pd.date_range(start = Start_date[:7], end = End_date[:7] ,freq='M'))+1
我只是使用月份来创建日期范围并计算长度。
from datetime import datetime
from dateutil import relativedelta
def get_months(d1, d2):
date1 = datetime.strptime(str(d1), '%Y-%m-%d')
date2 = datetime.strptime(str(d2), '%Y-%m-%d')
print (date2, date1)
r = relativedelta.relativedelta(date2, date1)
months = r.months + 12 * r.years
if r.days > 0:
months += 1
print (months)
return months
assert get_months('2018-08-13','2019-06-19') == 11
assert get_months('2018-01-01','2019-06-19') == 18
assert get_months('2018-07-20','2019-06-19') == 11
assert get_months('2018-07-18','2019-06-19') == 12
assert get_months('2019-03-01','2019-06-19') == 4
assert get_months('2019-03-20','2019-06-19') == 3
assert get_months('2019-01-01','2019-06-19') == 6
assert get_months('2018-09-09','2019-06-19') == 10
一个班轮，用于查找两个日期之间按月递增的日期时间列表。
import datetime
from dateutil.rrule import rrule, MONTHLY
strt_dt = datetime.date(2001,1,1)
end_dt = datetime.date(2005,6,1)
dates = [dt for dt in rrule(MONTHLY, dtstart=strt_dt, until=end_dt)]
你可以使用类似的东西：
import datetime
days_in_month = 365.25 / 12 # represent the average of days in a month by year
month_diff = lambda end_date, start_date, precision=0: round((end_date - start_date).days / days_in_month, precision)
start_date = datetime.date(1978, 12, 15)
end_date = datetime.date(2012, 7, 9)
month_diff(end_date, start_date) # should show 403.0 months
这对我有用 -
from datetime import datetime
from dateutil import relativedelta
date1 = datetime.strptime('2011-08-15 12:00:00', '%Y-%m-%d %H:%M:%S')
date2 = datetime.strptime('2012-02-15', '%Y-%m-%d')
r = relativedelta.relativedelta(date2, date1)
r.months * (r.years+1)
获取结束月份（相对于开始月份的年份和月份，例如2011年1月= 13，如果您的开始日期从2010年10月开始），然后生成开始月份和结束月份的日期时间，如下所示：
dt1, dt2 = dateRange
start_month=dt1.month
end_months=(dt2.year-dt1.year)*12 + dt2.month+1
dates=[datetime.datetime(year=yr, month=mn, day=1) for (yr, mn) in (
((m - 1) / 12 + dt1.year, (m - 1) % 12 + 1) for m in range(start_month, end_months)
)]
如果两个日期都在同一年，它也可以简单地写成：
dates=[datetime.datetime(year=dt1.year, month=mn, day=1) for mn in range(dt1.month, dt2.month + 1)]
你可以使用dateutil模块中的rrule轻松计算出来：
from dateutil import rrule
from datetime import date
print(list(rrule.rrule(rrule.MONTHLY, dtstart=date(2013, 11, 1), until=date(2014, 2, 1))))
会给你：
[datetime.datetime(2013, 11, 1, 0, 0),
datetime.datetime(2013, 12, 1, 0, 0),
datetime.datetime(2014, 1, 1, 0, 0),
datetime.datetime(2014, 2, 1, 0, 0)]
This post指甲！使用dateutil.relativedelta。
from datetime import datetime
from dateutil import relativedelta
date1 = datetime.strptime(str('2011-08-15 12:00:00'), '%Y-%m-%d %H:%M:%S')
date2 = datetime.strptime(str('2012-02-15'), '%Y-%m-%d')
r = relativedelta.relativedelta(date2, date1)
r.months
@ Vin-G有点美化解决方案。
import datetime
def monthrange(start, finish):
months = (finish.year - start.year) * 12 + finish.month + 1
for i in xrange(start.month, months):
year = (i - 1) / 12 + start.year
month = (i - 1) % 12 + 1
yield datetime.date(year, month, 1)
您也可以使用arrow库。这是一个简单的例子：
from datetime import datetime
import arrow
start = datetime(2014, 1, 17)
end = datetime(2014, 6, 20)
for d in arrow.Arrow.range('month', start, end):
print d.month, d.format('MMMM')
这将打印：
1 January
2 February
3 March
4 April
5 May
6 June
希望这可以帮助！