python处理时间

 

 

from datetime import datetime
from datetime import timedelta


# strptime： 将字符串解析为事件对象。 和 strftime 互为逆操作。 to parse a string to datetime and time objects respectively
# strftime： 将时间格式化为字符串。 和 strptime 互为逆操作。
# timedelta：用于计算时间差。 object represents a duration, the difference between two dates or times.
# datetime.timedelta([days[, seconds[, microseconds[, milliseconds[, minutes[, hours[, weeks]]]]]]])

start_time = '2021010812'
# 字符串到时间对象的转换
start_time_obj = datetime.strptime(start_time, '%Y%m%d%H')

hours = 1
# 减去，得到详情递推的时间
new_start_time_obj = start_time_obj - timedelta(hours=hours)
# 对时间进行格式化
new_start_time = new_start_time_obj.strftime('%Y%m%d%H')

 

Examples of working with datetime objects 写道

>>> from datetime import datetime, date, time
>>> # Using datetime.combine()
>>> d = date(2005, 7, 14)
>>> t = time(12, 30)
>>> datetime.combine(d, t)
datetime.datetime(2005, 7, 14, 12, 30)
>>> # Using datetime.now() or datetime.utcnow()
>>> datetime.now()
datetime.datetime(2007, 12, 6, 16, 29, 43, 79043) # GMT +1
>>> datetime.utcnow()
datetime.datetime(2007, 12, 6, 15, 29, 43, 79060)
>>> # Using datetime.strptime()
>>> dt = datetime.strptime("21/11/06 16:30", "%d/%m/%y %H:%M")
>>> dt
datetime.datetime(2006, 11, 21, 16, 30)
>>> # Using datetime.timetuple() to get tuple of all attributes
>>> tt = dt.timetuple()
>>> for it in tt:
... print it
...
2006 # year
11 # month
21 # day
16 # hour
30 # minute
0 # second
1 # weekday (0 = Monday)
325 # number of days since 1st January
-1 # dst - method tzinfo.dst() returned None
>>> # Date in ISO format
>>> ic = dt.isocalendar()
>>> for it in ic:
... print it
...
2006 # ISO year
47 # ISO week
2 # ISO weekday
>>> # Formatting datetime
>>> dt.strftime("%A, %d. %B %Y %I:%M%p")
'Tuesday, 21. November 2006 04:30PM'
>>> 'The {1} is {0:%d}, the {2} is {0:%B}, the {3} is {0:%I:%M%p}.'.format(dt, "day", "month", "time")
'The day is 21, the month is November, the time is 04:30PM.'

  

Examples of working with timedelta objects 写道

>>> from datetime import timedelta
>>> year = timedelta(days=365)
>>> another_year = timedelta(weeks=40, days=84, hours=23,
... minutes=50, seconds=600) # adds up to 365 days
>>> year.total_seconds()
31536000.0
>>> year == another_year
True
>>> ten_years = 10 * year
>>> ten_years, ten_years.days // 365
(datetime.timedelta(3650), 10)
>>> nine_years = ten_years - year
>>> nine_years, nine_years.days // 365
(datetime.timedelta(3285), 9)
>>> three_years = nine_years // 3;
>>> three_years, three_years.days // 365
(datetime.timedelta(1095), 3)
>>> abs(three_years - ten_years) == 2 * three_years + year
True

 

 

Directive Description Example Output

%a	Weekday as locale’s abbreviated name.	Sun, Mon, …, Sat (en_US) So, Mo, …, Sa (de_DE)
%A	Weekday as locale’s full name.	Sunday, Monday, …, Saturday (en_US) Sonntag, Montag, …, Samstag (de_DE)
%w	Weekday as a decimal number, where 0 is Sunday and 6 is Saturday.	0, 1, 2, 3, 4, 5, 6
%d	Day of the month as a zero-padded decimal number.	01, 02, …, 31
%b	Month as locale’s abbreviated name.	Jan, Feb, …, Dec (en_US) Jan, Feb, …, Dez (de_DE)
%B	Month as locale’s full name.	January, February, …, December (en_US) Januar, Februar, …, Dezember (de_DE)
%m	Month as a zero-padded decimal number.	01, 02 … 12
%y	Year without century as a zero-padded decimal number.	01, 02, … 99
%Y	Year with century as a decimal number.	0001, 0002, … , 9999
%H	Hour (24-hour clock) as a zero-padded decimal number.	01, 02, … , 23
%I	Hour (12-hour clock) as a zero-padded decimal number.	01, 02, … , 12
%p	Locale’s equivalent of either AM or PM.	AM, PM (en_US) am, pm (de_DE)
%M	Minute as a zero-padded decimal number.	01, 02, … , 59
%S	Second as a zero-padded decimal number.	01, 02, … , 59
%f	Microsecond as a decimal number, zero-padded on the left.	000000, 000001, …, 999999 Not applicable with time module.
%z	UTC offset in the form ±HHMM[SS] (empty string if the object is naive).	(empty), +0000, -0400, +1030
%Z	Time zone name (empty string if the object is naive).	(empty), UTC, IST, CST
%j	Day of the year as a zero-padded decimal number.	001, 002, …, 366
%U	Week number of the year (Sunday as the first day of the week) as a zero padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0.	00, 01, …, 53
%W	Week number of the year (Monday as the first day of the week) as a decimal number. All days in a new year preceding the first Monday are considered to be in week 0.	00, 01, …, 53
%c	Locale’s appropriate date and time representation.	Tue Aug 16 21:30:00 1988 (en_US) Di 16 Aug 21:30:00 1988 (de_DE)
%x	Locale’s appropriate date representation.	08/16/88 (None) 08/16/1988 (en_US) 16.08.1988 (de_DE)
%X	Locale’s appropriate time representation.	21:30:00 (en_US) 21:30:00 (de_DE)
%%	A literal ‘%’ character.	%