Python时间，日期，时间戳之间转换

1.将字符串的时间转换为时间戳
    方法:
        a = "2013-10-10 23:40:00"
        将其转换为时间数组
        import time
        timeArray = time.strptime(a, "%Y-%m-%d %H:%M:%S")
    转换为时间戳:
    timeStamp = int(time.mktime(timeArray))
    timeStamp == 1381419600
 
2.字符串格式更改
    如a = "2013-10-10 23:40:00",想改为 a = "2013/10/10 23:40:00"
    方法:先转换为时间数组,然后转换为其他格式
    timeArray = time.strptime(a, "%Y-%m-%d %H:%M:%S")
    otherStyleTime = time.strftime("%Y/%m/%d %H:%M:%S", timeArray)
 
 
3.时间戳转换为指定格式日期:
    方法一:
        利用localtime()转换为时间数组,然后格式化为需要的格式,如
        timeStamp = 1381419600
        timeArray = time.localtime(timeStamp)
        otherStyleTime = time.strftime("%Y-%m-%d %H:%M:%S", timeArray)
        otherStyletime == "2013-10-10 23:40:00"
 
    方法二:
        import datetime
        timeStamp = 1381419600
        dateArray = datetime.datetime.utcfromtimestamp(timeStamp)
        otherStyleTime = dateArray.strftime("%Y-%m-%d %H:%M:%S")
        otherStyletime == "2013-10-10 23:40:00"
 
4.获取当前时间并转换为指定日期格式
    方法一:
        import time
        获得当前时间时间戳
        now = int(time.time())  ->这是时间戳
        转换为其他日期格式,如:"%Y-%m-%d %H:%M:%S"
        timeArray = time.localtime(timeStamp)
        otherStyleTime = time.strftime("%Y-%m-%d %H:%M:%S", timeArray)
 
    方法二:
        import datetime
        获得当前时间
        now = datetime.datetime.now()  ->这是时间数组格式
        转换为指定的格式:
        otherStyleTime = now.strftime("%Y-%m-%d %H:%M:%S")
 
5.获得三天前的时间
    方法:
        import time
        import datetime
        先获得时间数组格式的日期
        threeDayAgo = (datetime.datetime.now() - datetime.timedelta(days = 3))
        转换为时间戳:
            timeStamp = int(time.mktime(threeDayAgo.timetuple()))
        转换为其他字符串格式:
            otherStyleTime = threeDayAgo.strftime("%Y-%m-%d %H:%M:%S")
    注:timedelta()的参数有:days,hours,seconds,microseconds
 
6.给定时间戳,计算该时间的几天前时间:
    timeStamp = 1381419600
    先转换为datetime
    import datetime
    import time
    dateArray = datetime.datetime.utcfromtimestamp(timeStamp)
    threeDayAgo = dateArray - datetime.timedelta(days = 3)
    参考5,可以转换为其他的任意格式了
 
python tm_isdst = -1, 0, 1 datetime module
Python 里的tm_isdst 
DST 是daylight saving time, 意思是：夏令时
在python的time, datetime模块下，按照struct_time格式输出时间，最后的一个tm_isdst的值就是告知是否为夏令时。
tm_isdst = 1 的时候表示时间是夏令时，
　　　　值为0的时候表示非夏令时
　　　　值为-1的时候表示时间不确定是否是夏令时 
获取本月的时间戳范围
#!/usr/bin/env python
# -*- coding:utf-8 -*-
# Author:Henry  17607168727@163.com
import calendar
import datetime
import time


def return_time_stamp():
    # 获取当天日期
    today = datetime.datetime.today()
    year = today.year
    month = today.month
    # 查询当月总天数
    month_end_days = calendar.monthrange(year,month)[1]
    # 构造本月第一天文本格式时间
    first_day_str = """%s-%s-%s 00:00:00""" % (year,month,1)
    # 构造本月最后一天文本格式时间
    end_day_str = """%s-%s-%s 00:00:00""" % (year,month,month_end_days)
    # 转成时间数组
    first_time_array = time.strptime(first_day_str, "%Y-%m-%d %H:%M:%S")
    end_time_array = time.strptime(end_day_str, "%Y-%m-%d %H:%M:%S")
    first_time_stamp = int(time.mktime(first_time_array))
    end_time_stamp = int(time.mktime(end_time_array))
    print(year,month,month_end_days,first_time_array,end_time_array,first_time_stamp,end_time_stamp)
    return [first_time_stamp,end_time_stamp]

if __name__ == '__main__':
    
    return_time_stamp()