Python commonly used time, datetime processing, pythondatetime

Python commonly used time, datetime processing, pythondatetime

In python, time has three formats:

Float,

Struct tuple(Time. struct_time or datetime. datetime ),

Str

 

Common:

Float-->Struct tuple: Time.Localtime(Float)

Struct time tuple-->Str: Time.Strftime(Format,Struct time tuple)

Str-->Struct time tuple: Time.Strptime(Str, format)

Struct time tuple-->Float: Time.Mktime(Struct time tuple)

Struct time tuple-->Datetime:Datetime (* time_tuple [0: 6])

 

Float-->Datetime: Datetime. datetime.Fromtimestamp(Float)

Datetime --> str: Datetime. Strftime(Format,Datetime)

Str-->Datetime:Datetime. strptime(Str, format)

Datetime-->Struct time tuple: Datetime.Timetuple()

 

Note:

Time is based on float, the decimal point is millisecond, And the integer part is second. (Java is millisecond, so, python_time * 1000 = Java_time)

Datetime is int, Which is omitted in milliseconds. Datetime tuple is less than struct_time

 

1. Current Time

>>> Import time >>> time. time () 1450681042.751 >>> time. localtime (time. time () time. struct_time (maid = 2015, tm_mon = 12, tm_mday = 21, tm_hour = 15, tm_min = 0, tm_sec = 2, tm_wday = 0, tm_yday = 355, tm_isdst = 0) >>> time. strftime ('% Y-% m-% d % H: % M: % s', time. localtime (time. time () '2017-12-21 15:01:28 '>>> from datetime import datetime >>> datetime. now () datetime. datetime (2015, 12, 21, 14, 58, 38,279 000)> datetime. today () datetime. datetime (2015, 12, 21, 14, 59, 20,204 000) >>> now = datetime. now () >>> now. year, now. month, now. day, now. hour, now. minute, now. second, now. microsecond >>> now. isocalendar () # Monday, week 1, 52nd (2015, 52, 1) >>> now. isoweekday () # day of the week, 1: Monday; and now. the returned value of weekday () starts from 0 and 1.

 

2. Date string --> date

>>> s='2015-12-21 15:01:28'>>> timeTuple = datetime.strptime(s, '%Y-%m-%d %H:%M:%S')datetime.datetime(2015, 12, 21, 15, 1, 28)>>> datetime.datetime.strftime('%Y/%m/%d %H:%M:%S', timeTuple)

>>> s='2015-12-21 15:01:28'>>> timeTuple = datetime.strptime(s, '%Y-%m-%d %H:%M:%S')time.struct_time(tm_year=2015, tm_mon=12, tm_mday=21, tm_hour=15, tm_min=1, tm_sec=28, tm_wday=0, tm_yday=355, tm_isdst=-1)>>> time.strftime('%Y/%m/%d %H:%M:%S',timeTuple)

Time and date formatting symbol in python: % y two-digit year representation (00-99) % Y four-digit year representation (000-9999) % m month (01-12) one day (0-31) % H 24-hour (0-23) % I 12-hour (01-12) in % d month) % M minutes (00 = 59) % S seconds (00-59) % a local simplified week name % A local full week name % B local simplified month name % B local full month name % c local corresponding date representation and Time Representation % j Years one day (001-366) % p local. m. or P. m. % U the number of weeks in a year (00-53) Sunday is the beginning of the week % w Week (0-6 ), sunday is the beginning of a week % W the number of weeks in a year (00-53) monday is the start of the week % x local corresponding date represents % X local corresponding time represents % Z Current Time Zone name % itself

 

3. Timestamp

>>> time.mktime(time.strptime(s,'%Y-%m-%d %H:%M:%S'))1450681288.0>>> int(time.time())

# timestamp to time tuple in UTCtimestamp = 1226527167.595983time_tuple = time.gmtime(timestamp)print repr(time_tuple)

# timestamp to time tuple in local timetimestamp = 1226527167.595983time_tuple = time.localtime(timestamp)print repr(time_tuple)

 

2. Date addition and subtraction

import datetimenow = datetime.datetime.now() # datetime.datetime(2015, 12, 16, 15, 6, 37, 420000)dayOfweek = datetime.datetime.isoweekday()if dayOfweek == 1: # Monday    last_time = now + datetime.timedelta(days=-3)else:    last_time = now + datetime.timedelta(days=-1)

Turn: http://www.cnblogs.com/snow-backup/p/5063665.html