Python 如何将字符串转换为时间日期 datetime 格式

本教程来介绍 Python 如何将字符串 string 转换为 datetime 对象,随后列举出来代码例子来实现流行的时间格式的转化。

datetime.strptime()

在以前的教程中,我们介绍了使用 datetime.strftime() 方法将 datetime 转化为字符串。这里我们将用 datetime.strptime() 方法来实现逆转换。两种方法中的差别 fp 分别对应着 format(格式)和 parse(解析)。

datetime.strptime() 按照给定的 datetime 格式来解析字符串,解析成功的话,返回 datetime 对象。

下面的例子是 datetime.strptime() 的简单使用例子。

from datetime import datetime

datetime.strptime("2018-01-31", "%Y-%m-%d")

它的返回结果是,

datetime.datetime(2018, 1, 31, 0, 0)

The directives of the string format codes are listed here for your reference

Directive Meaning Example
%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, …, 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. 00, 01, …, 99
%Y Year with century as a decimal number. 0001, 0002, …, 2013, 2014, …, 9998, 9999
%H Hour (24-hour clock) as a zero-padded decimal number. 00, 01, …, 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. 00, 01, …, 59
%S Second as a zero-padded decimal number. 00, 01, …, 59
%f Microsecond as a decimal number, zero-padded on the left. 000000, 000001, …, 999999
%z UTC offset in the form ±HHMMSS. (empty), +0000, -0400, +1030
%Z Time zone name (empty string if the object is naive). (empty), UTC, EST, 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. %

datetime.strptime() 举例

7-May-2013 格式

from datetime import datetime

dateString = "7-May-2018"
dateFormatter = "%u-%b-%Y"
datetime.strptime(dateString, dateFormatter)

输出为,

datetime.datetime(2013, 5, 1, 0, 0)

31/12/2018 格式

from datetime import datetime

dateString = "31/12/2013"
dateFormatter = "%d/%m/%Y"
datetime.strptime(dateString, dateFormatter)

输出

datetime.datetime(2013, 12, 31, 0, 0)

Mon, July 16 2018格式

from datetime import datetime

dateString = "31/12/2013"
dateFormatter = "%d/%m/%Y"
datetime.strptime(dateString, dateFormatter)

输出

datetime.datetime(2018, 7, 16, 0, 0)

Monday, July 16, 2018 20:01:56 格式

from datetime import datetime

dateString = "Monday, July 16, 2018 20:01:56"
dateFormatter = "%A, %B %d, %Y %H:%M:%S"
datetime.strptime(dateString, dateFormatter)

输出

datetime.datetime(2018, 7, 16, 20, 1, 56)