Python常用的日期时间处理方法示例

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


    #给定日期向后N天的日期
    def dateadd_day(days):
      d1 = datetime.datetime.now()
      d3 = d1 + datetime.timedelta(days)
      return d3


    #昨天
    def getYesterday():
      today = datetime.date.today()
      oneday = datetime.timedelta(days=1)
      yesterday = today - oneday
      return yesterday


    #今天
    def getToday():
      return datetime.date.today()


    #获取给定参数的前几天的日期，返回一个list
    def getDaysBefore(num):
      today = datetime.date.today()
      oneday = datetime.timedelta(days=1)
      li = []
      for i in range(0, num):
        #今天减一天，一天一天减
        today = today - oneday
        #把日期转换成字符串
        li.append(datetostr(today))
      return li


    #将字符串转换成datetime类型
    def strtodatetime(datestr, format):
      return datetime.datetime.strptime(datestr, format)


    #时间转换成字符串,格式为2015-02-02
    def datetostr(date):
      return str(date)[0:10]


    #时间转换成字符串,格式为2015-02-02
    def datetostr_secod(date):
      return str(date)[0:19]


    #两个日期相隔多少天，例：2015-2-04和2015-3-1
    def datediff(beginDate, endDate):
      format = "%Y-%m-%d"
      bd = strtodatetime(beginDate, format)
      ed = strtodatetime(endDate, format)
      oneday = datetime.timedelta(days=1)
      count = 0
      while bd != ed:
        ed = ed - oneday
        count += 1
      return count


    #两个日期之间相差的秒
    def datediff_seconds(beginDate, endDate):
      format = "%Y-%m-%d %H:%M:%S"
      if " " not in beginDate or ':' not in beginDate:
        bformat = "%Y-%m-%d"
      else:
        bformat = format
      if " " not in endDate or ':' not in endDate:
        eformat = "%Y-%m-%d"
      else:
        eformat = format
      starttime = strtodatetime(beginDate, bformat)
      endtime = strtodatetime(endDate, eformat)
      ret = endtime - starttime
      return ret.days * 86400 + ret.seconds


    #获取两个时间段的所有时间,返回list
    def getDays(beginDate, endDate):
      format = "%Y-%m-%d"
      begin = strtodatetime(beginDate, format)
      oneday = datetime.timedelta(days=1)
      num = datediff(beginDate, endDate) + 1
      li = []
      for i in range(0, num):
        li.append(datetostr(begin))
        begin = begin + oneday
      return li


    #获取当前年份 是一个字符串
    def getYear(date=datetime.date.today()):
      return str(date)[0:4]


    #获取当前月份 是一个字符串
    def getMonth(date=datetime.date.today()):
      return str(date)[5:7]


    #获取当前天 是一个字符串
    def getDay(date=datetime.date.today()):
      return str(date)[8:10]


    #获取当前小时 是一个字符串
    def getHour(date=datetime.datetime.now()):
      return str(date)[11:13]


    #获取当前分钟 是一个字符串
    def getMinute(date=datetime.datetime.now()):
      return str(date)[14:16]


    #获取当前秒 是一个字符串
    def getSecond(date=datetime.datetime.now()):
      return str(date)[17:19]


    def getNow():
      return datetime.datetime.now()


    print dateadd_day(10)
    #2015-02-14 16:41:13.275000

    print getYesterday()
    #2015-02-03

    print getToday()
    #2015-02-04

    print getDaysBefore(3)
    #['2015-02-03', '2015-02-02', '2015-02-01']

    print datediff('2015-2-01', '2015-10-05')
    #246

    print datediff_seconds('2015-02-04', '2015-02-05')
    #86400

    print datediff_seconds('2015-02-04 22:00:00', '2015-02-05')
    #7200

    print getDays('2015-2-03', '2015-2-05')
    #['2015-02-03', '2015-02-04', '2015-02-05']

    print datetostr_secod(getNow())
    #2015-02-04 16:46:47

    print str(getYear(dateadd_day(-50))) + '-'\
      + getMonth() + '-'\
      + getDay() + ' '\
      + getHour() + ':'\
      + getMinute() + ':'\
      + getSecond()
    #2014-02-04 16:59:04

    print getNow()
    #2015-02-04 16:46:47.454000