python的datetime模块及timedelta模块

import datetime

import time

now = datetime.datetime.now()

# print(now)

today = datetime.datetime.today()

# print(today)

strftime = datetime.datetime.strftime(now, '%Y/%m/%d %H:%M:%S')

# print(strftime) #2019/08/20 17:31:56

# 日期加1天，减一天，减去1个小时，减去1分钟都用timedelta可以实现

timedelta = datetime.timedelta(days=1)

today_timedelta = today + timedelta

today_timedelta_2 = today - timedelta

# print(today_timedelta) #2019-08-21 17:38:21.678296

# print(today_timedelta_2) # 2019-08-19 17:38:21.678296

datetime_hours = datetime.timedelta(hours=1)

# print(today+datetime_hours) #2019-08-20 18:40:20.140040

datetime_minutes = datetime.timedelta(minutes=15)

# print(today+datetime_minutes) #2019-08-20 17:56:20.555111

datetime_seconds = datetime.timedelta(seconds=60)

# print(today+datetime_seconds) #2019-08-20 17:43:13.314686