import time
time1 = time.time()
time.sleep(15)
time2 = time.time()
print time2 - time1

>>> import datetime,time
>>> now = time.strftime("%Y-%m-%d %H:%M:%S")
>>> print now
2016-04-30 17:02:26
>>> now = datetime.datetime.now()
>>> print now

>>> import datetime
>>> yestoday = datetime.datetime.now() - datetime.timedelta(days=1)
>>> t1 = "%s-00-00-00" % yestoday.strftime("%Y-%m-%d")
>>> t2 = "%s-23-59-59" % yestoday.strftime("%Y-%m-%d")
>>> print 't1', t1
t1 2016-04-29-00-00-00
>>> print 't2', t2
t2 2016-04-29-23-59-59

>>> d1 = datetime.datetime.now()
>>> d3 = d1 + datetime.timedelta(hours=10)
>>> d3.ctime()
'Sun May 1 03:09:58 2

>>> import datetime
>>> starttime = datetime.datetime.now()
>>> endtime = datetime.datetime.now()
>>> starttime = datetime.datetime.now()
>>> endtime = datetime.datetime.now()
>>> print endtime - starttime
0:00:07.390988
>>> print (endtime - starttime).seconds
7
>>> print (endtime - starttime).microseconds
390988

>>> import os
>>> statinfo=os.stat(r"C:/1.txt")
>>> statinfo
(33206, 0L, 0, 0, 0, 0, 29L, 1201865413, 1201867904, 1201865413)

>>> statinfo.st_mtime
1201865413.8952832

>>> import time
>>> time.localtime(statinfo.st_ctime)
(2008, 2, 1, 19, 30, 13, 4, 32, 0)

#! coding:utf-8
''''' 日期相关的操作 '''
from datetime import datetime
from datetime import timedelta
import calendar
DATE_FMT = '%Y-%m-%d'
DATETIME_FMT = '%Y-%m-%d %H:%M:%S'
DATE_US_FMT = '%d/%m/%Y'
'''''
格式化常用的几个参数
Y ： 1999
y ：99
m : mouth 02 12
M : minute 00-59
S : second
d : day
H : hour
'''
def dateToStr(date):
  '''''把datetime类型的时间格式化自己想要的格式'''
  return datetime.strftime(date, DATETIME_FMT)
def strToDate(strdate):
  '''''把str变成日期用来做一些操作'''
  return datetime.strptime(strdate, DATETIME_FMT)
def timeElement():
  '''''获取一个时间对象的各个元素'''
  now = datetime.today()
  print 'year: %s month: %s day: %s' %(now.year, now.month, now.day)
  print 'hour: %s minute: %s second: %s' %(now.hour, now.minute, now.second)
  print 'weekday: %s ' %(now.weekday()+1) #一周是从0开始的
def timeAdd():
  '''''
  时间的加减，前一天后一天等操作
  datetime.timedelta([days[, seconds[, microseconds[, milliseconds[, minutes[, hours[, weeks]]]]]]])
  参数可以是正数也可以是负数
  得到的对象可以加也可以减 乘以数字和求绝对值
  '''
  atime = timedelta(days=-1)
  now = datetime.strptime('2001-01-30 11:01:02', DATETIME_FMT)
  print now + atime
  print now - abs(atime)
  print now - abs(atime)*31
def lastFirday():
   today = datetime.today()
   targetDay = calendar.FRIDAY
   thisDay = today.weekday()
   de = (thisDay - targetDay) % 7
   res = today - timedelta(days=de)
   print res
def test():
  print dateToStr(datetime.today())
  print strToDate('2013-01-31 12:00:01')
  timeElement()
  timeAdd()
  lastFirday()
if __name__=='__main__':
  test()

Connected to pydev debugger (build 141.1899)
2016-05-18 10:40:26
2013-01-31 12:00:01
year: 2016 month: 5 day: 18
hour: 10 minute: 41 second: 13
weekday: 3
2001-01-29 11:01:02
2001-01-29 11:01:02
2000-12-30 11:01:02
2016-05-13 10:41:37.001000