If only timedelta had a month argument in it\'s constructor. So what\'s the simplest way to do this?
EDIT: I wasn\'t thinking too hard about this as was poin
def month_sub(year, month, sub_month):
result_month = 0
result_year = 0
if month > (sub_month % 12):
result_month = month - (sub_month % 12)
result_year = year - (sub_month / 12)
else:
result_month = 12 - (sub_month % 12) + month
result_year = year - (sub_month / 12 + 1)
return (result_year, result_month)
>>> month_sub(2015, 7, 1)
(2015, 6)
>>> month_sub(2015, 7, -1)
(2015, 8)
>>> month_sub(2015, 7, 13)
(2014, 6)
>>> month_sub(2015, 7, -14)
(2016, 9)