#-*- 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()