python 实现得到当前时间偏移day天后的日期方法

import datetime
#以当前时间作为起始点，days=-7向前偏移7天，days=7向后偏移7天
time_now = datetime.datetime.now()
time = (time_now+datetime.timedelta(days=7)).strftime("%Y%m%d")
print(time)

import datetime
from dateutil.relativedelta import relativedelta
#以当前时间作为起始点，days=-7向前偏移7天，days=7向后偏移7天
time_now = datetime.datetime.now()
time = (time_now+datetime.timedelta(days=7)).strftime("%Y%m%d")
print(time)
#以当前时间为起始点，偏移一个月
time_1=(time_now+relativedelta(months=-1)).strftime("%Y%m%d")
print(time_1)