import time t = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime()) print(t) timestamp = time.time() tuple_time = time.localtime(timestamp) print(tuple_time) print(time.strftime("%Y-%m-%d %H:%M:%S", tuple_time))
import time import datetime time_str = "2023-02-19 23:07:21" time_struct = time.strptime(time_str, "%Y-%m-%d %H:%M:%S") print(time_struct) print(time.mktime(time_struct)) print(int(time.mktime(time_struct)))
Python提供了多个内置模块用于操作日期时间,像calendar,time,datetime。time模块我在之前的文章已经有所介绍,它提供 的接口与C标准库time.h基本一致。相比于time模块,datetime模块的接口则更直观、更容易调用。今天就来讲讲datetime模块。
datetime模块定义了两个常量:datetime.MINYEAR和datetime.MAXYEAR,分别表示datetime所能表示的最 小、最大年份。其中,MINYEAR = 1,MAXYEAR = 9999。(对于偶等玩家,这个范围已经足够用矣~~)
注 :上面这些类型的对象都是不可变(immutable)的。
下面详细介绍这些类的使用方式。
date类
date类表示一个日期。日期由年、月、日组成(地球人都知道~~)。date类的构造函数如下:
class datetime.date(year, month, day):参数的意义就不多作解释了,只是有几点要注意一下:
date类定义了一些常用的类方法与类属性,方便我们操作:
import time import datetime time_str = "2023-02-19 23:07:21" time_struct = time.strptime(time_str, "%Y-%m-%d %H:%M:%S") print(datetime.datetime.now()) computed_time = datetime.datetime.now() - datetime.timedelta(days=3) print(computed_time) timestamp = time.mktime(computed_time.timetuple()) print(timestamp) time_str = time.strftime("%Y-%m-%d %H:%M:%S", computed_time.timetuple()) print(time_str)
import time import datetime time_str = "2023-02-19 23:07:21" time_struct = time.strptime(time_str, "%Y-%m-%d %H:%M:%S") currentDate = datetime.datetime.now() print(time.strftime("%Y-%m-%d %H:%M:%S", currentDate.timetuple())) print(currentDate.year) print(currentDate.month) print(currentDate.day) print(currentDate.hour) print(currentDate.minute) print(currentDate.second)
date提供的实例方法和属性:
import time from datetime import datetime, date time_str = "2023-02-19 23:07:21" time_struct = time.strptime(time_str, "%Y-%m-%d %H:%M:%S") now = date(2023, 1, 18) print(time.strftime("%Y-%m-%d %H:%M:%S", now.timetuple())) print(now.weekday()) print(now.isoformat())
date还对某些操作进行了重载,它允许我们对日期进行如下一些操作:
注: 对日期进行操作时,要防止日期超出它所能表示的范围。
import time from datetime import datetime, date, timedelta time_str = "2023-02-19 23:07:21" time_struct = time.strptime(time_str, "%Y-%m-%d %H:%M:%S") currentDate = date.today() print(time.strftime("%Y-%m-%d %H:%M:%S", currentDate.timetuple())) time_delta = currentDate - timedelta(days=1) print(time.strftime("%Y-%m-%d %H:%M:%S", time_delta.timetuple())) print(currentDate > time_delta) print(currentDate - time_delta) print(time_delta + timedelta(days=3))
datetime类提供的实例方法与属性(很多属性或方法在date和time中已经出现过,在此有类似的意义,这里只罗列这些方法名,具体含义不再逐个展开介绍,可以参考上文对date与time类的讲解。):
像date一样,也可以对两个datetime对象进行比较,或者相减返回一个时间间隔对象,或者日期时间加上一个间隔返回一个新的日期时间对象。