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'>



# 获取时间差的秒数
import datetime
t1 = datetime.datetime.strptime("2019-08-24 10:30:00", "%Y-%m-%d %H:%M:%S")
t2 = datetime.datetime.strptime("2019-08-24 12:30:00", "%Y-%m-%d %H:%M:%S")
interval_time = (t2 - t1).seconds  
total_interval_time = (t2 - t1).total_seconds() 
print interval_time, total_interval_time      # 结果：7200 7200.0         
t1 = datetime.datetime.strptime("2019-08-24 10:30:00", "%Y-%m-%d %H:%M:%S")
t2 = datetime.datetime.strptime("2019-08-25 12:30:00", "%Y-%m-%d %H:%M:%S")
interval_time = (t2 - t1).seconds  
total_interval_time = (t2 - t1).total_seconds() 
print interval_time, total_interval_time      # 结果：7200 93600.0 



# 时间格式的相互转换 
import datetime
# 1.datetime转字符串：
t1 = datetime.datetime.now()
t2 = datetime.datetime.strftime(t1, '%Y-%m-%d %H:%M:%S')
t3 = t1.strftime('%Y-%m-%d %H:%M:%S')
print t1, type(t1)      # 结果：2019-01-15 14:26:05.198000   <type 'datetime.datetime'>
print t2, type(t2)      # 结果：2019-01-15 14:26:05   <type 'str'>
print t3, type(t3)      # 结果：2019-01-15 14:26:05   <type 'str'>
# 2.字符串转datetime：
t4 = datetime.datetime.strptime(t2, '%Y-%m-%d %H:%M:%S')
print t4, type(t4)      # 结果：2019-01-15 14:26:05   <type 'datetime.datetime'>