>>> import time

>>> time.time()               #时间戳 秒级别

1519212085.6211221            #从1970年到现在一共度过1519212085秒；

>>> time.time()/3600/24/365   #48年 1970-2018年有这么多秒 1h=3600s

48.17390346104816

>>> time.localtime()          #本地时间

time.struct_time(tm_year=2018, tm_mon=2, tm_mday=21, tm_hour=20, tm_min=8, tm_sec=33, tm_wday=2, tm_yday=52, tm_isdst=0)

>>> time.localtime(2342342434)

time.struct_time(tm_year=2044, tm_mon=3, tm_mday=23, tm_hour=18, tm_min=40, tm_sec=34, tm_wday=2, tm_yday=83, tm_isdst=0)

>>> a=time.localtime()

>>> a

time.struct_time(tm_year=2018, tm_mon=2, tm_mday=21, tm_hour=19, tm_min=28, tm_sec=45, tm_wday=2, tm_yday=52, tm_isdst=0)

>>> '%s-%s-%d'%(a.tm_year,a.tm_mon,a.tm_mday)

'2018-2-21'

>>> time.mktime(a)            #把localtime()时间反转时间成时间戳

1519214861.0 

0  tm_year    #年 1970-2018

1  tm_mon     #月 1-12

2  tm_mday    #日 1-31

3  tm_hour    #时 0-23

4  tm_min     #分 0-59

5  tm_sec     #秒 0-59

6  tm_wday    #一周中得第几天 0-6

7  tm_yday    #一年中得第几天 0-365

8  tm_isdst   #是否是夏令时  0-1

>>> time.gmtime()     #比北京时间晚8点 UTC时区（0时区）

time.struct_time(tm_year=2018, tm_mon=2, tm_mday=21, tm_hour=11, tm_min=50, tm_sec=46, tm_wday=2, tm_yday=52, tm_isdst=0)

>>> time.sleep(2)     #睡一会 单位为 秒

>>> time.asctime()    #表示时间得另外一种方法

'Wed Feb 21 20:53:43 2018'

>>> time.ctime()      #表示时间得另外一种方法

'Wed Feb 21 20:57:16 2018'

>>> time.ctime(3123)

'Thu Jan  1 08:52:03 1970'

>>> time.ctime(0)

'Thu Jan  1 08:00:00 1970'

>>> time.strftime('%Y-%m-%d %H:%M:%S')      #表示时间 字符串

'2018-02-21 21:04:48'

>>> a=time.localtime(2432423423)

>>> a

time.struct_time(tm_year=2047, tm_mon=1, tm_mday=30, tm_hour=9, tm_min=10, tm_sec=23, tm_wday=2, tm_yday=30, tm_isdst=0)

>>> time.strftime('%Y-%m-%d %H:%M:%S',a)     #表示某一时间戳得 字符串

'2047-01-30 09:10:23'

>>> time.strftime('%Y-%m-%d %H:%M:%S %a',a)  #a 周几

'2047-01-30 09:10:23 Wed'

>>> time.strftime('%Y-%m-%d %H:%M:%S %A',a)  #A 周几

'2047-01-30 09:10:23 Wednesday'

>>> time.strftime('%y-%m-%d %H:%M:%S %b')    #b 月

'18-02-21 21:22:19 Feb'

>>> time.strftime('%y-%m-%d %H:%M:%S %B')    #B 月

'18-02-21 21:22:29 February'

>>> time.strftime('%Y-%m-%d %H:%M:%S %p',a)  #p 上午下午

'2047-01-30 09:10:23 AM'

>>> time.strftime('%Y-%m-%d %H:%M:%S %U')    #U 一年得第几周

'2018-02-21 21:08:15 07'

>>> time.strftime('%Y-%m-%d %H:%M:%S %w')    #w 一周得第几天

'2018-02-21 21:09:55 3'

>>> time.strftime('%y-%m-%d %H:%M:%S %z')    #z 东8区时间

'18-02-21 21:10:38 +0800'

>> time.strftime('%Y-%m-%d %H:%M:%S %Z')     #Z 时间标准

'2018-02-21 21:28:22 中国标准时间'

>>> s=time.strftime('%Y-%m-%d %H:%M:%S')     #时间字符串 格式  时间戳来回转换

>>> s

'2018-02-21 21:32:19'

>>> s2= time.strptime(s,'%Y-%m-%d %H:%M:%S')

>>> s2

time.struct_time(tm_year=2018, tm_mon=2, tm_mday=21, tm_hour=21, tm_min=32, tm_sec=19, tm_wday=2, tm_yday=52, tm_isdst=-1)

>>> time.mktime(s2)

1519219939.0

字符串转时间格式对应表

Meaning    Notes

%a    Locale’s abbreviated weekday name.

%A    Locale’s full weekday name.

%b    Locale’s abbreviated month name.

%B    Locale’s full month name.

%c    Locale’s appropriate date and time representation.

%d    Day of the month as a decimal number [01,31].

%H    Hour (24-hour clock) as a decimal number [00,23].

%I    Hour (12-hour clock) as a decimal number [01,12].

%j    Day of the year as a decimal number [001,366].

%m    Month as a decimal number [01,12].

%M    Minute as a decimal number [00,59].

%p    Locale’s equivalent of either AM or PM.    (1)

%S    Second as a decimal number [00,61].    (2)

%U    Week number of the year (Sunday as the first day of the week) as a decimal number [00,53]. All days in a new year preceding the first Sunday are considered to be in week 0.    (3)

%w    Weekday as a decimal number [0(Sunday),6].

%W    Week number of the year (Monday as the first day of the week) as a decimal number [00,53]. All days in a new year preceding the first Monday are considered to be in week 0.    (3)

%x    Locale’s appropriate date representation.

%X    Locale’s appropriate time representation.

%y    Year without century as a decimal number [00,99].

%Y    Year with century as a decimal number.

%z    Time zone offset indicating a positive or negative time difference from UTC/GMT of the form +HHMM or -HHMM, where H represents decimal hour digits and M represents decimal minute digits [-23:59, +23:59].

%Z    Time zone name (no characters if no time zone exists).

%%    A literal '%' character.

方法：

>>> a=datetime.datetime.now()

>>> a

datetime.datetime(2018, 2, 21, 21, 59, 57, 526811)

>>> a.year

2018

>>> a.timetuple()

time.struct_time(tm_year=2018, tm_mon=2, tm_mday=21, tm_hour=21, tm_min=59, tm_sec=57, tm_wday=2, tm_yday=52, tm_isdst=-1)

>>> d2=datetime.date.fromtimestamp(time.time())       #根据时间戳快速拿到年月日

>>> d2

datetime.date(2018, 2, 21)

>>> d2.timetuple()        #注意 时分秒 丢了

time.struct_time(tm_year=2018, tm_mon=2, tm_mday=21, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=2, tm_yday=52, tm_isdst=-1)

时间运算：

>>> datetime.datetime.now()-datetime.timedelta(days=1)

datetime.datetime(2018, 2, 20, 22, 13, 4, 891830)

>>> datetime.datetime.now()-datetime.timedelta(days=3)

datetime.datetime(2018, 2, 18, 22, 14, 7, 771268)

>>> datetime.datetime.now()-datetime.timedelta(hours=3)

datetime.datetime(2018, 2, 21, 19, 14, 33, 758609)

>>> datetime.datetime.now()+datetime.timedelta(hours=3)

datetime.datetime(2018, 2, 22, 1, 14, 48, 426850)

>>> datetime.datetime.now()+datetime.timedelta(minutes=10)

datetime.datetime(2018, 2, 21, 22, 25, 32, 615892)

>>> datetime.datetime.now()+datetime.timedelta(seconds=10)

datetime.datetime(2018, 2, 21, 22, 16, 29, 661140) 

时间替换：

>>> s=datetime.datetime.now()

>>> s

datetime.datetime(2018, 2, 21, 22, 21, 34, 62949)

>>> s.replace(year=2016)

datetime.datetime(2016, 2, 21, 22, 21, 34, 62949)

>>> s.replace(year=2016,month=8)

datetime.datetime(2016, 8, 21, 22, 21, 34, 62949)

>>> s.replace(year=2016,month=8,day=2)

datetime.datetime(2016, 8, 2, 22, 21, 34, 62949) 

#把datetime转成字符串

def datetime_toString(dt):

    return dt.strftime("%Y-%m-%d-%H")

#把字符串转成datetime

def string_toDatetime(string):

    return datetime.strptime(string, "%Y-%m-%d-%H")

#把字符串转成时间戳形式

def string_toTimestamp(strTime):

    return time.mktime(string_toDatetime(strTime).timetuple())

#把时间戳转成字符串形式

def timestamp_toString(stamp):

    return time.strftime("%Y-%m-%d-%H", tiem.localtime(stamp))

#把datetime类型转外时间戳形式

def datetime_toTimestamp(dateTim):

    return time.mktime(dateTim.timetuple())

#coding=utf-8

import time

import datetime

def yes_time():

    #获取当前时间

    now_time = datetime.datetime.now()

    #当前时间减去一天 获得昨天当前时间

    yes_time = now_time + datetime.timedelta(days=-1)

    #格式化输出

    yes_time_str = yes_time.strftime('%Y-%m-%d %H:%M:%S')

    print yes_time_str  # 2017-11-01 22:56:02

def dif_time():

    #计算两个时间之间差值

    now_time = datetime.datetime.now()

    now_time = now_time.strftime('%Y-%m-%d %H:%M:%S')

    d1 = datetime.datetime.strptime('2017-10-16 19:21:22', '%Y-%m-%d %H:%M:%S')

    d2 = datetime.datetime.strptime(now_time, '%Y-%m-%d %H:%M:%S')

    #间隔天数

    day = (d2 - d1).days

    #间隔秒数

    second = (d2 - d1).seconds

    print day   #

    print second  #13475  注意这样计算出的秒数只有小时之后的计算额 也就是不包含天之间差数

def unix_time():

    #将python的datetime转换为unix时间戳

    dtime = datetime.datetime.now()

    un_time = time.mktime(dtime.timetuple())

    print un_time  #1509636609.0

    #将unix时间戳转换为python  的datetime

    unix_ts = 1509636585.0

    times = datetime.datetime.fromtimestamp(unix_ts)

    print times  #2017-11-02 23:29:45