第十一天：时间与日期

一、datetime

1、date

2、time

import datetime
datetime.MAXYEAR
datetime.MINYEAR
today = datetime.date.today()
today
today.year
today.month
today.day
today.weekday()
today.isoweekday()

9999
1
datetime.date(2019, 9, 7)
2019
9
7
5
6

3、datetime

• year
• month
• day

birthdate = datetime.date(2010, 3, 12)
birthdate.year
birthdate.day
t = datetime.time(15, 46, 32)
t.hour
t.minute
t.second

2010
12
15
46
32

import datetime
now = datetime.datetime.now()
now
now.year
now.second
now.microsecond #微秒

datetime.datetime(2019, 9, 7, 20, 14, 45, 543196)
2019
7
45
543196

4、格式转换

• 字符串到日期时间 datetime.datetime.strptime(‘txt’, ‘%Y-%m-%d’)
• 日期时间到字符串 datetime.datetime.strftime( ‘%Y/%m/%d’)

import datetime
s = '2018-2-23'
t = datetime.datetime.strptime(s, '%Y-%m-%d') #Y要大写
t
now = datetime.datetime.now()
now
txt = now.strftime('%Y/%m/%d')
txt

datetime.datetime(2018, 2, 23, 0, 0)
datetime.datetime(2019, 9, 7, 20, 19, 16, 226808)
'2019/09/07'

• 占位符
  %Y 四位年份
  %y 两位年份
  %m 两位月份
  %d 两位日期
  %H 两位小时
  %M 两位分钟
  %S 两位秒数
  %f 微秒
  %w 星期-0-6

5、时间差 timedelta

import datetime
d = datetime.datetime(2018, 3, 5, 22, 44)
birthdate = datetime.datetime(2016, 5, 2, 19, 33, 44)
d - birthdate #相隔了672天11416秒

datetime.timedelta(days=672, seconds=11416)

• days
• seconds
• hours

diff = d - birthdate
diff.days
diff.seconds 
diff.total_seconds() #实际相隔的秒数

672
11416
58072216.0

o = datetime.datetime(2008, 8, 8, 20, 8)
o + datetime.timedelta(days=100)
result = d + datetime.timedelta(days = -100)
result
d + datetime.timedelta(seconds=3000)

datetime.datetime(2008, 11, 16, 20, 8)
datetime.datetime(2017, 11, 25, 22, 44)
datetime.datetime(2018, 3, 5, 23, 34)