python---时间模块

datetime模块：

# -*- coding:utf-8 -*-
import datetime

# 日期格式话模版
format_pattern = "%Y-%m-%d %H:%M:%S"

# 将当前时间格式化输出
t1 = datetime.datetime.now()
print t1,type(t1)      # 结果：2019-01-13 21:35:36.433000   <type 'datetime.datetime'>
# 3天后的时间
t2 = datetime.datetime.now()+datetime.timedelta(3)
print t2,type(t2)      # 结果：2019-01-16 21:35:36.433000   <type 'datetime.datetime'>
# 3天前的时间
t3 = datetime.datetime.now()+datetime.timedelta(-3)
print t3,type(t3)      # 结果：2019-01-10 21:35:36.433000   <type 'datetime.datetime'>
# datetime的两个方法
t4 = datetime.timedelta(3)
t5 = datetime.timedelta(-3)
print t4,type(t4)      # 结果：3 days, 0:00:00      <type 'datetime.timedelta'>
print t5,type(t5)      # 结果：-3 days, 0:00:00     <type 'datetime.timedelta'>