python datetime模块
该模块的时间有限时限：1 - 9999
dir(datetime)
1 from datetime import datetime, timedelta, timezone 2 3 dt = datetime.now() 4 t = dt.timestamp() 5 6 dt1 = datetime.fromtimestamp(t) 7 8 utc_dt = datetime.utcfromtimestamp(t) 9 10 tz_utc_8 = timezone(timedelta(hours=8)) 11 utc_dt1 = dt.replace(tzinfo=tz_utc_8) 12 13 str1 = dt.strftime("%Y-%m-%d %X") 14 str2 = dt.ctime() 15 16 dt2 = datetime.strptime('2016-11-27', "%Y-%m-%d") 17 18 st = dt.timetuple() 19 20 dt3 = dt + timedelta(days=2, hours=1)
练习：
（1）现在时间
（2）指定时间
（3）闰年判定
（4）今年第几天
（5）今天第几周
（6）程序运行时间
（7）判定星期几
（8）时间日期比较
1 "（1）现在时间" 2 from datetime import datetime 3 4 now1 = datetime.now() 5 now2 = datetime.today() 6 print(now1) 7 print(now2) 8 9 "（2）指定时间" 10 dt = datetime(2016, 12, 3, 21, 17) 11 print(dt) 12 13 "（3）闰年判定" 14 import calendar 15 16 if calendar.isleap(2016): 17 print("leap year") 18 19 "（4）今年第几天" 20 import time 21 22 print(time.localtime().tm_yday) 23 print(time.strftime("%j")) 24 25 "（5）今天第几周" 26 print(time.strftime("%W")) 27 28 "（6）程序运行时间" 29 t1 = time.time() 30 t2 = time.time() 31 print("run time: ", t2 - t1) 32 33 t1 = time.clock() 34 t2 = time.clock() 35 print("{}".format(t2)) 36 37 "（7）判定星期几" 38 "0-6" 39 print(datetime.now().weekday()) 40 41 "（8）时间日期比较" 42 43 dt1 = datetime(2016, 12, 3) 44 dt2 = datetime(2016, 12, 4) 45 print(dt1 > dt2) 46 print(dt1 == dt2) 47 print(dt1 < dt2) 48 print(dt1 is dt2) 49 print(dt1 is not dt2)
