今天要为大家收集分享的Python学习（http://www.maiziedu.com/course/python-px/）代码为：Python 按月增加datetime月份的问题源码。可能有同学看不明白什么是Python 按月增加datetime？其实简单的理解python datetime增加月份的问题，就是一些人的日常工作是需要对月份加减进行相关操作计算。
DateTime是什么：DateTime是时间类型，datetime是Python处理日期和时间的标准库。还有python time模块
Python 按月增加datetime月份的问题源码如下：（Python源码中注释部分多为英文，大家可自行翻译）
#coding=utf-8
 
import datetime
 
# input datetime1, and an month offset
# return the result datetime
 
def datetime_offset_by_month(datetime1, n = 1):
 
    # create a shortcut object for one day
    one_day = datetime.timedelta(days = 1)
 
    # first use div and mod to determine year cycle
    q,r = divmod(datetime1.month + n, 12)
 
    # create a datetime2
    # to be the last day of the target month
    datetime2 = datetime.datetime(
        datetime1.year + q, r + 1, 1) - one_day
 
'''
   if input date is the last day of this month
   then the output date should also be the last
   day of the target month, although the day
   www.iplaypython.com
   may be different.
   for example:
   datetime1 = 8.31
   datetime2 = 9.30
'''
 
    if datetime1.month != (datetime1 + one_day).month:
        return datetime2
 
'''
    if datetime1 day is bigger than last day of
    target month, then, use datetime2
    for example:
    datetime1 = 10.31
    datetime2 = 11.30
'''
 
    if datetime1.day >= datetime2.day:
        return datetime2
 
'''
 then, here, we just replace datetime2's day
 with the same of datetime1, that's ok.
'''
 
    return datetime2.replace(day = datetime1.day)
 
 
d1 = datetime.datetime(2008, 8, 17)
d2 = datetime_offset_by_month(d1, 13)
 
print '2008-8-17 + 13 month'
print d2
print
 
 
d1 = datetime.datetime(2008, 8, 31)
d2 = datetime_offset_by_month(d1, 13)
 
print '2008-8-31 + 13 month'
print d2
print
 
 
d1 = datetime.datetime(2007, 1, 30)
d2 = datetime_offset_by_month(d1, 13)
 
print '2007-1-30 + 13 month'
print d2
print
 
result = """
2008-8-17 + 13 month
2009-09-17 00:00:00
 
2008-8-31 + 13 month
2009-09-30 00:00:00
 
2007-1-30 + 13 month
2008-02-29 00:00:00
"""