5ol.cc 发表于 2018-8-15 09:49:25

Python-基础-时间日期处理小结


[*]  Python-基础-时间日期处理小结
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[*]  datetime <=> string
[*]  datetime <=> timetuple
[*]  datetime <=> date
[*]  datetime <=> timestamp
[*]  1. 获取当前datetime
[*]  2. 获取当天date
[*]  3. 获取明天/前N天
[*]  4. 获取当天开始和结束时间(00:00:00 23:59:59)
[*]  5. 获取两个datetime的时间差
[*]  6. 获取本周/本月/上月最后一天
[*]  1. datetime
[*]  2. timestamp
[*]  3. time tuple
[*]  4. string
[*]  5. date


[*]  涉及对象
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[*]  datetime基本操作
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[*]  关系转换
[*]  关系转换例子
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  好久没写文了, 继续清理笔记, 都是一些小结之类的, 源码分析以及在做系统中一些细节难点等, 后续逐步发
  另外打个广告, 甜品礼物, 坐标深圳, 有兴趣的同学可以给我发邮件, 非python职位会转到对应同事:)
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  原则, 以datetime为中心, 起点或中转, 转化为目标对象, 涵盖了大多数业务场景中需要的日期转换处理
  步骤:
1. 掌握几种对象及其关系  
2. 了解每类对象的基本操作方法
  
3. 通过转化关系转化
涉及对象
1. datetime
>>> import datetime>>> now = datetime.datetime.now()>>> nowdatetime.datetime(2015, 1, 12, 23, 9, 12, 946118)>>> type(now)<type 'datetime.datetime'>2. timestamp
>>> import time>>> time.time()1421075455.5682433. time tuple
>>> import time>>> time.localtime()time.struct_time(tm_year=2015, tm_mon=1, tm_mday=12, tm_hour=23, tm_min=10, tm_sec=30, tm_wday=0, tm_yday=12, tm_isdst=0)4. string
>>> import datetime>>> datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")'2015-01-12 23:13:08'5. date
>>> import datetime>>> datetime.datetime.now().date()datetime.date(2015, 1, 12)datetime基本操作
1. 获取当前datetime
>>> import datetime>>> datetime.datetime.now()datetime.datetime(2015, 1, 12, 23, 26, 24, 475680)2. 获取当天date
>>> datetime.date.today()datetime.date(2015, 1, 12)3. 获取明天/前N天
  明天
>>> datetime.date.today() + datetime.timedelta(days=1)datetime.date(2015, 1, 13)  三天前
>>> datetime.datetime.now()datetime.datetime(2015, 1, 12, 23, 38, 55, 492226)>>> datetime.datetime.now() - datetime.timedelta(days=3)datetime.datetime(2015, 1, 9, 23, 38, 57, 59363)4. 获取当天开始和结束时间(00:00:00 23:59:59)
>>> datetime.datetime.combine(datetime.date.today(), datetime.time.min)datetime.datetime(2015, 1, 12, 0, 0)>>> datetime.datetime.combine(datetime.date.today(), datetime.time.max)datetime.datetime(2015, 1, 12, 23, 59, 59, 999999)5. 获取两个datetime的时间差
>>> (datetime.datetime(2015,1,13,12,0,0) - datetime.datetime.now()).total_seconds()44747.7680756. 获取本周/本月/上月最后一天
  本周
>>> today = datetime.date.today()>>> todaydatetime.date(2015, 1, 12)>>> sunday = today + datetime.timedelta(6 - today.weekday())>>> sundaydatetime.date(2015, 1, 18)  本月
>>> import calendar>>> today = datetime.date.today()>>> _, last_day_num = calendar.monthrange(today.year, today.month)>>> last_day = datetime.date(today.year, today.month, last_day_num)>>> last_daydatetime.date(2015, 1, 31)  获取上个月的最后一天(可能跨年)
>>> import datetime>>> today = datetime.date.today()>>> first = datetime.date(day=1, month=today.month, year=today.year)>>> lastMonth = first - datetime.timedelta(days=1)关系转换
  几个关系之间的转化
  Datetime Object / String / timestamp / time tuple
关系转换例子
datetime <=> string
  datetime -> string
>>> import datetime>>> datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")'2015-01-12 23:13:08'  string -> datetime
>>> import datetime>>> datetime.datetime.strptime("2014-12-31 18:20:10", "%Y-%m-%d %H:%M:%S")datetime.datetime(2014, 12, 31, 18, 20, 10)datetime <=> timetuple
  datetime -> timetuple
>>> import datetime>>> datetime.datetime.now().timetuple()time.struct_time(tm_year=2015, tm_mon=1, tm_mday=12, tm_hour=23, tm_min=17, tm_sec=59, tm_wday=0, tm_yday=12, tm_isdst=-1)  timetuple -> datetime
timetuple => timestamp => datetime [看后面datetime<=>timestamp]datetime <=> date
  datetime -> date
>>> import datetime>>> datetime.datetime.now().date()datetime.date(2015, 1, 12)  date -> datetime
>>> datetime.date.today()datetime.date(2015, 1, 12)>>> today = datetime.date.today()>>> datetime.datetime.combine(today, datetime.time())datetime.datetime(2015, 1, 12, 0, 0)>>> datetime.datetime.combine(today, datetime.time.min)datetime.datetime(2015, 1, 12, 0, 0)datetime <=> timestamp
  datetime -> timestamp
>>> now = datetime.datetime.now()>>> timestamp = time.mktime(now.timetuple())>>> timestamp1421077403.0  timestamp -> datetime
>>> datetime.datetime.fromtimestamp(1421077403.0)datetime.datetime(2015, 1, 12, 23, 43, 23)
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