2-datetime 模块

发布时间:2019-10-11 09:02:19编辑:auto阅读(2019)

    datetime

    时间转字符串

    在我们的使用中,我们常常需要将时间转换为字符串,用来作为文件的名字或者用于加密字符的输出等等。例子:

    from datetime import datetime 
    datetime.strftime(datetime.now(),"%Y-%m-%d %H:%M:%S")

    记忆方式也很简单,str from time

    字符转时间

    有时候我们需要将一个字符给转换为时间对象

    from datetime import datetime 
    >>> datetime.strptime('2018-09-09',"%Y-%m-%d")
    datetime.datetime(2018, 9, 9, 0, 0)

    时间戳的转换

    import time 
    from datetime import datetime 
    stamp = time.time()
    datetime.fromtimestamp(stamp)

    timedelta

    import datetime
    print('microseconds:', datetime.timedelta(microseconds=1))
    print('milliseconds:', datetime.timedelta(milliseconds=1))
    print('seconds :', datetime.timedelta(seconds=1))
    print('minutes :', datetime.timedelta(minutes=1))
    print('hours :', datetime.timedelta(hours=1))
    print('days :', datetime.timedelta(days=1))
    print('weeks :', datetime.timedelta(weeks=1))

    加 就是 延后几秒; 减 就是提前几秒

    转换格式

    Symbol Meaning Example
    %a Abbreviated weekday name 'Wed'
    %A Full weekday name 'Wednesday'
    %w Weekday number: 0 (Sunday) through 6 (Saturday) '3'
    %d Day of the month (zero padded) '13'
    %b Abbreviated month name 'Jan'
    %B Full month name 'January'
    %m Month of the year '01'
    %y Year without century '18'
    %Y Year with century '2018'
    %H Hour from 24-hour clock '17'
    %I Hour from 12-hour clock '05'
    %p AM/PM 'PM'
    %M Minutes '00'
    %S Seconds '00'
    %f Microseconds '000000'
    %z UTC offset for time zone–aware objects '-0500'
    %Z Time zone name 'EST'
    %j Day of the year '013'
    %W Week of the year '02'
    %c Date and time representation for the current locale 'Wed Jan 13 17:00:00 2016'
    %x Date representation for the current locale '01/13/16'
    %X Time representation for the current locale '17:00:00'
    %% A literal % character '%'

    tips

    工作中经常需要用到美国时间,做一个记录。 utc晚了8个小时,所以要减去即是美国时间

    datetime.strftime(datetime.utcnow()-timedelta(hours=8),'%Y-%m-%d %H:%M:%S')

    参考

    《The Python3 Standard Library By Example》

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