二十三、python中的time和datetime模块

A、time模块

  1. sleep():强制等待

import time
import datetime

print("start to sleep.....")
time.sleep(5)
print("wake up ...........")

'''
2.time.time():当前系统的时间戳
'''
print(time.time())
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1533021214.0050707
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'''
3.time.ctime():当前系统时间
'''
print (time.ctime())
print(time.ctime(time.time()-86400))#昨天的此刻

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Tue Jul 31 15:13:34 2018
Mon Jul 30 15:13:34 2018
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'''
4.time.gmtime():将时间转化成struct_time格式
'''
print (time.gmtime())
time_obj=time.gmtime(time.time()-86400)  #昨天的此刻（将时间戳转化成struct_time格式）

print (time_obj)
print (str(time_obj.tm_year)+"-"+str(time_obj.tm_mon)+"-"+str(time_obj.tm_mday))

print("%s-%s-%s %s:%s:%s" %(time_obj.tm_year,time_obj.tm_mon,time_obj.tm_mday,time_obj.tm_hour,time_obj.tm_min,time_obj.tm_sec))

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time.struct_time(tm_year=2018, tm_mon=7, tm_mday=31, tm_hour=7, tm_min=32, tm_sec=9, tm_wday=1, tm_yday=212, tm_isdst=0)
　time.struct_time(tm_year=2018, tm_mon=7, tm_mday=30, tm_hour=7, tm_min=32, tm_sec=9, tm_wday=0, tm_yday=211, tm_isdst=0)
　2018-7-30
　2018-7-30 7:32:9

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'''
4.1.字符串格式化（扩展）
%s:字符串
%d：整型
%f：浮点型
'''

time_obj=time.gmtime(time.time()-86400)  #昨天的此刻

print("%s-%s-%s %s:%s:%s" %(time_obj.tm_year,time_obj.tm_mon,time_obj.tm_mday,time_obj.tm_hour,time_obj.tm_min,time_obj.tm_sec))

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2018-7-30 7:32:9

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'''
5.localtime():将时间戳转化成struct_time格式，返回本地的时间
'''
print (time.localtime(time.time()-86400))

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time.struct_time(tm_year=2018, tm_mon=7, tm_mday=31, tm_hour=14, tm_min=51, tm_sec=20, tm_wday=1, tm_yday=212, tm_isdst=0)

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'''
6.time.mktime(time.localtime()):将struct_time转化成时间戳格式
'''
print (time.mktime(time.localtime()))

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1533106558.0

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'''
7.time.strptime():将字符串格式日期转化成struct_time格式
'''

print (time.strptime("2018-08-01 15:02","%Y-%m-%d %H:%M"))

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　time.struct_time(tm_year=2018, tm_mon=8, tm_mday=1, tm_hour=15, tm_min=2, tm_sec=0, tm_wday=2, tm_yday=213, tm_isdst=-1)

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'''
8.time.strftime():将时间对象转成指定的字符串格式
'''
print (time.strftime("%Y-%m-%d %H:%M:%S",time.gmtime()))
print (time.strftime("%Y-%m-%d %H:%M:%S",time.localtime()))

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2018-08-01 07:05:10
   2018-08-01 15:05:10

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'''
9.time.asctime():返回时间格式"Fri Aug 19 11:14:16 2016
'''
print(time.asctime())

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Wed Aug  1 15:06:53 2018

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B、datatime

'''
1.datetime.date.today():打印当天的日期，格式：2018-08-01
'''
print (datetime.date.today())

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2018-08-01

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'''
2.datetime.date.fromtimestamp(time.time()):将时间戳转化成日期格式
'''
print (datetime.date.fromtimestamp(time.time()))

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2018-08-01

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'''
3.datetime.datetime.now():返回当前时间，时分秒
   datetime.datetime.now().timetuple()：将当前时间转化成struct_time格式
'''
current_time=datetime.datetime.now()
print(current_time)
print(current_time.timetuple())

--------------------------- 

2018-08-01 15:20:18.638428
    time.struct_time(tm_year=2018, tm_mon=8, tm_mday=1, tm_hour=15, tm_min=20, tm_sec=18, tm_wday=2, tm_yday=213, tm_isdst=-1)

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'''

4.datetime.datetime.now().replace(yyyy,mm,dd):将当前时间替换成指定时间

  datetime.datetime.now().replace():指定格式为空的话返回当前日期

   ' '
　　current_time=datetime.datetime.now()
　　print(current_time.replace())
　　print(current_time.replace(2066,12,12))

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2018-08-01 15:27:29.508072
    2066-12-12 15:27:29.508072

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'''
5.时间的加减
'''
print (datetime.datetime.now()+datetime.timedelta(days=10)) #比现在加10天
print (datetime.datetime.now()-datetime.timedelta(days=10)) #比现在减10天
print (datetime.datetime.now()+datetime.timedelta(hours=2)) #比现在加10小时
print (datetime.datetime.now()-datetime.timedelta(seconds=10)) #比现在减10秒
print (datetime.datetime.now()-datetime.timedelta(minutes=10)) #比现在减10分钟
print (datetime.datetime.now()+datetime.timedelta(weeks=1)) #比现在加一周

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　　2018-08-11 15:56:19.873044
　　2018-07-22 15:56:19.873044
　　2018-08-01 17:56:19.873044
　　2018-08-01 15:56:09.873044
　　2018-08-01 15:46:19.873044
　　2018-08-08 15:56:19.873044

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