python日期與時間相關

import time與datetime

# -*-coding: utf-8 -*-
"""
python時間相關
"""
import time
import datetime

目前的 timestamp

timestampNow=time.time()
print timestampNow


>>> 1495355013.86

目前的 datetime

dateNow = datetime.datetime.now()
print dateNow


>>> 2017-05-21 16:23:33.858233

今天的 datetime

dateToday = datetime.date.today()
print dateToday


>>> 2017-05-21

昨天的 datetime

yesterday = datetime.date.today()-datetime.timedelta(1)
print yesterday


>>> 2017-05-20

昨天的 datetime 輸出指定格式字串

yesterday = datetime.date.today()-datetime.timedelta(1)
# dateTime yesterday in %m-%d-%y (月-日-年)
print(yesterday.strftime('%m-%d-%y'))


>>> 05-20-17

n分鐘前的datetime

dateAgo=datetime.datetime.now()-datetime.timedelta(minutes=10)
# dateTime 10 minutes ago
print dateAgo


>>> 2017-05-21 16:13:34.098177

改變時區(UTC+0的時間轉為UTC+8)

dateNow = ((datetime.datetime.now())+datetime.timedelta(hours=8)) #Taiwan is UTC+8
dateNowStr = dateNow.strftime("%Y%m%d") # 輸出成年月日
print dateNowStr


>>> 2017-05-21 

n分鐘前的timestamp

timestampAgo=(time.time()-10*60)
# timestamp 10 minutes ago
print timestampAgo


>>> 1495354414.09

得到指定格式的日期與時間

# "格式為 [年/月/日 時:分:秒] 的時間:"
print time.strftime("%Y/%m/%d %H:%M:%S")


>>> 2017/05/21 16:23:34

指定格式的日期字串轉成時間物件

# "字串為 2017/05/21 的時間:"
dateString = "2017/05/21"
dateObj = datetime.datetime.strptime(dateString, "%Y/%m/%d")
print dateObj


>>> 2017-05-21 00:00:00 

timestamp 轉 datetime

timestampNow=time.time()
date_time = datetime.datetime.fromtimestamp(timestampNow)
print timestampNow


>>> 1495355014.1

print date_time


>>> 2017-05-21 16:23:34.098222

datetime 轉 timestamp

dtNow=datetime.datetime.now()
print dtNow


>>> 2017-05-21 16:23:34.098243

dtNow_timestamp=time.mktime(dtNow.timetuple())
print dtNow_timestamp


>>> 1495355014.0

以datetime 得 星期幾

def get_week_day(date):
    week_day_dict = {
        0 : '星期一',
        1 : '星期二',
        2 : '星期三',
        3 : '星期四',
        4 : '星期五',
        5 : '星期六',
        6 : '星期天',
    }
    day = date.weekday()
    return week_day_dict[day]

dateTimeNow = datetime.datetime.now()
weekdayIndex = dateTimeNow.weekday()
weekday = get_week_day(datetime.datetime.now())

print(dateTimeNow)


>>> 2017-05-21 16:23:34.098267

print(weekdayIndex)


>>> 6

print(weekday)


>>> 星期天