Python-基础-时间日期处理小结

• Python-基础-时间日期处理小结
  • 涉及对象
    • 1. datetime
    • 2. timestamp
    • 3. time tuple
    • 4. string
    • 5. date
  • datetime基本操作
    • 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
  • 关系转换
  • 关系转换例子
    • datetime <=> string
    • datetime <=> timetuple
    • datetime <=> date
    • datetime <=> timestamp

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() >>> now datetime.datetime(2015, 1, 12, 23, 9, 12, 946118) >>> type(now) <type 'datetime.datetime'> 

2. timestamp

>>> import time
>>> time.time() 1421075455.568243 

3. 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() 44747.768075 

6. 获取本周/本月/上月最后一天

本周

>>> today = datetime.date.today() >>> today datetime.date(2015, 1, 12) >>> sunday = today + datetime.timedelta(6 - today.weekday()) >>> sunday datetime.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_day datetime.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()) >>> timestamp 1421077403.0 

timestamp -> datetime

>>> datetime.datetime.fromtimestamp(1421077403.0) datetime.datetime(2015, 1, 12, 23, 43, 23)