Python下time模块和datetime模块的使用

时间模块

time模块

时间表示格式:

1.格式化时间: 【 2018-01-01 01:00:00 】

2.时间戳: 【 1518407077.940927 】 -> 秒数(从1970开始到现今)

3.以元组方式表示，九个元素(格式化元组)

  元素如下:
    (1)  tm_year=2018,  # 年
    (2)  tm_mon=2,      # 月
    (3)  tm_mday=12,    # 日
    (4)  tm_hour=11,    # 小时
    (5)  tm_min=49,     # 分钟
    (6)  tm_sec=13,     # 秒
    (7)  tm_wday=0,     # 0(Mon)-6(Sun) 从0(周一)开始数 -> 6(周天)
    (8)  tm_yday=43,    # 今年的第几天
    (9)  tm_isdst=0     # 时区，如果是1，则表示夏令时

使用

• timezone 返回时间标准实际与当前时间差(秒数)

  In [45]: time.timezone
  
  Out[45]: -28800
  
  In [46]: time.timezone / 3600
  
  Out[46]: -8.0   # 中国时间与标准时间相差8小时

  ---

• altzone 与 timezone 差不多
  

  ---

• daylight 查看你是否使用了夏令时，0表示没有使用

  In [50]: time.daylight
  
  Out[50]: 0

  ---

• time () 返回当前的时间戳

  In [37]: time.time()
  
  Out[37]: 1518407588.8324711

• sleep () 使程序暂停几秒

  In [51]: time.sleep(3)
  
  In [52]:

  ---

• gmtime () 传入时间戳，返回格式化元组 【 UTC时区 】

  In [54]: time.gmtime(time.time())
  
  Out[54]: time.struct_time(tm_year=2018, tm_mon=2, tm_mday=12, tm_hour=4, tm_min=7, tm_sec=50, tm_wday=0, tm_yday=43, tm_isdst=0)

  ---

• localtime () 传入时间戳,返回格式化元组(不传入参数,默认当前时间) 【 根据本地区域决定 】

  In [55]: time.localtime()
  
  Out[55]: time.struct_time(tm_year=2018, tm_mon=2, tm_mday=12, tm_hour=12, tm_min=10, tm_sec=13, tm_wday=0, tm_yday=43, tm_isdst=0)

  In [56]: time.localtime(123123123)
  
  Out[56]: time.struct_time(tm_year=1973, tm_mon=11, tm_mday=26, tm_hour=8, tm_min=52, tm_sec=3, tm_wday=0, tm_yday=330, tm_isdst=0)

  ---

取出元组数据:

  In [57]: a = time.localtime()

  In [58]: a.tm_year # 取出年份
  Out[58]: 2018

  In [59]: a.tm_mon  # 取出月份
  Out[59]: 2

  In [60]: a.tm_sec # 取出分钟
  Out[60]: 54

• mktime () 由元组转换为时间戳

  In [63]: time.mktime(time.localtime())
  
  Out[63]: 1518409129.0

  ---

• strftime (format,tuple) --> string 自定义生成格式化时间 -> string
  1. 格式化操作

     %Y Year with century as a decimal number.
     %m Month as a decimal number [01,12].
     %d Day of the month as a decimal number [01,31].
     %H Hour (24-hour clock) as a decimal number [00,23].
     %M Minute as a decimal number [00,59].
     %S Second as a decimal number [00,61].
     %z Time zone offset from UTC.
     %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.
     %I Hour (12-hour clock) as a decimal number [01,12].
     %p Locale‘s equivalent of either AM or PM

  2. 使用:
  
  In [67]: time.strftime(‘%Y-%m-%d‘,time.localtime())
  Out[67]: ‘2018-02-12‘

  ---

• ctime () 传入时间戳,返回文本型时间

  In [69]: time.ctime()
  Out[69]: ‘Mon Feb 12 12:30:44 2018‘
  
  In [77]: time.ctime(123123123)
  Out[77]: ‘Mon Nov 26 08:52:03 1973‘

  ---

• asctime () 传入格式化元组,返回文本型时间

  In [79]: time.asctime(time.localtime(123123))
  Out[79]: ‘Fri Jan  2 18:12:03 1970‘

  In [80]: time.asctime()
  Out[80]: ‘Mon Feb 12 12:34:23 2018‘

datetime模块

datetie模块

• datetime.now () 返回当前时间

  In [156]: print(datetime.datetime.now())
  
  In [156]: 2018-02-12 12:39:43.309016

时间运算

In [174]: datetime.datetime.now() + datetime.timedelta(1)
Out[174]: datetime.datetime(2018, 2, 13, 12, 43, 12, 301435)

In [175]: datetime.datetime.now() - datetime.timedelta(1)
Out[175]: datetime.datetime(2018, 2, 11, 12, 43, 28, 154795)

In [181]: datetime.datetime.now() + datetime.timedelta(hours=1)
Out[181]: datetime.datetime(2018, 2, 12, 13, 44, 54, 816476)

In [182]: datetime.datetime.now() + datetime.timedelta(hours=1)
Out[182]: datetime.datetime(2018, 2, 12, 13, 44, 56, 429732)

原文地址：http://blog.51cto.com/13155232/2071613