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python time时间模块

feifeifeisir 2018-08-24 14:17 原文

在Python中，通常有这三种方式来表示时间：时间戳、元组(struct_time)、格式化的时间字符串

(1)时间戳(timestamp) :通常来说，时间戳表示的是从1970年1月1日00:00:00开始按秒计算的偏移量。我们运行“type(time.time())”，返回的是float类型。

(2)时间元组(struct_time): struct_time元组共有9个元素共九个元素:(年，月，日，时，分，秒，一年中第几周，一年中第几天等）

(3)格式化的时间字符串(Format String)： ‘1999-12-06’   ‘%Y-%m-%d %X'等等

导入时间模块
>>>import time

#时间戳
>>>time.time()
1500875844.800804

#时间字符串
>>>time.strftime("%Y-%m-%d %X")
'2017-07-24 13:54:37'
>>>time.strftime("%Y-%m-%d %H-%M-%S")
'2017-07-24 13-55-04'

#时间元组:localtime将一个时间戳转换为当前时区的struct_time
time.localtime()
time.struct_time(tm_year=2017, tm_mon=7, tm_mday=24,
　　　　　　　　　　tm_hour=13, tm_min=59, tm_sec=37, 
                 tm_wday=0, tm_yday=205, tm_isdst=0)

小结：时间戳是计算机能够识别的时间；时间字符串是人能够看懂的时间；元组则是用来操作时间的

#时间戳-->结构化时间
#time.gmtime(时间戳)    #UTC时间，与英国伦敦当地时间一致
#time.localtime(时间戳) #当地时间。例如我们现在在北京执行这个方法：与UTC时间相差8小时，UTC时间+8小时 = 北京时间 
>>>time.gmtime(1500000000)
time.struct_time(tm_year=2017, tm_mon=7, tm_mday=14, tm_hour=2, tm_min=40, tm_sec=0, tm_wday=4, tm_yday=195, tm_isdst=0)
>>>time.localtime(1500000000)
time.struct_time(tm_year=2017, tm_mon=7, tm_mday=14, tm_hour=10, tm_min=40, tm_sec=0, tm_wday=4, tm_yday=195, tm_isdst=0)

#结构化时间-->时间戳　
#time.mktime(结构化时间)
>>>time_tuple = time.localtime(1500000000)
>>>time.mktime(time_tuple)
1500000000.0
#结构化时间-->字符串时间
#time.strftime("格式定义","结构化时间")  结构化时间参数若不传，则显示当前时间
>>>time.strftime("%Y-%m-%d %X")
'2017-07-24 14:55:36'
>>>time.strftime("%Y-%m-%d",time.localtime(1500000000))
'2017-07-14'

#字符串时间-->结构化时间
#time.strptime(时间字符串,字符串对应格式)
>>>time.strptime("2017-03-16","%Y-%m-%d")
time.struct_time(tm_year=2017, tm_mon=3, tm_mday=16, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=3, tm_yday=75, tm_isdst=-1)
计算时间差:
import time
true_time=time.mktime(time.strptime('2017-09-11 08:30:00','%Y-%m-%d %H:%M:%S'))
time_now=time.mktime(time.strptime('2017-09-12 11:00:00','%Y-%m-%d %H:%M:%S'))
dif_time=time_now-true_time
struct_time=time.gmtime(dif_time)
print('过去了%d年%d月%d天%d小时%d分钟%d秒'%(struct_time.tm_year-1970,struct_time.tm_mon-1,
                                       struct_time.tm_mday-1,struct_time.tm_hour,
                                       struct_time.tm_min,struct_time.tm_sec))

获取当前时间日月

# 今天日期   06.15
timer = time.strftime("%m.%d")
print(timer)   
# 昨天日期   06.14
timer = (date.today() + timedelta(days=-1)).strftime("%m.%d")
print(timer)
#  将时间字符串转化为datetime类型
start_date = datetime.datetime.strptime(start_time, "%Y-%m-%d %H:%M:%S")

获取本周，上周，本月，上月，本季的时间

import datetime
from datetime import timedelta
  
now = datetime.datetime.now()
  
# 今天
today = now
print('--- today = {}'.format(today))
  
# 昨天
yesterday = now - timedelta(days=1)
print('--- yesterday = {}'.format(yesterday))
  
# 明天
tomorrow = now + timedelta(days=1)
print('--- tomorrow = {}'.format(tomorrow))
  
# 当前季度
now_quarter = now.month / 3 if now.month % 3 == 0 else now.month / 3 + 1
print('--- now_quarter = {}'.format(now_quarter))
  
# 本周第一天和最后一天
this_week_start = now - timedelta(days=now.weekday())
this_week_end = now + timedelta(days=6 - now.weekday())
print('--- this_week_start = {} this_week_end = {}'.format(this_week_start, this_week_end))
  
# 上周第一天和最后一天
last_week_start = now - timedelta(days=now.weekday() + 7)
last_week_end = now - timedelta(days=now.weekday() + 1)
print('--- last_week_start = {} last_week_end = {}'.format(last_week_start, last_week_end))
  
# 本月第一天和最后一天
this_month_start = datetime.datetime(now.year, now.month, 1)
this_month_end = datetime.datetime(now.year, now.month + 1, 1) - timedelta(days=1)+ datetime.timedelta(
    hours=23, minutes=59, seconds=59)
print('--- this_month_start = {} this_month_end = {}'.format(this_month_start, this_month_end))
  
# 上月第一天和最后一天
last_month_end = this_month_start - timedelta(days=1)+ datetime.timedelta(
    hours=23, minutes=59, seconds=59)
last_month_start = datetime.datetime(last_month_end.year, last_month_end.month, 1)
print('--- last_month_end = {} last_month_start = {}'.format(last_month_end, last_month_start))
  
# 本季第一天和最后一天
month = (now.month - 1) - (now.month - 1) % 3 + 1
this_quarter_start = datetime.datetime(now.year, month, 1)
this_quarter_end = datetime.datetime(now.year, month + 3, 1) - timedelta(days=1)+ datetime.timedelta(
    hours=23, minutes=59, seconds=59)
print('--- this_quarter_start = {} this_quarter_end = {}'.format(this_quarter_start, this_quarter_end))
  
# 上季第一天和最后一天
last_quarter_end = this_quarter_start - timedelta(days=1)+ datetime.timedelta(
    hours=23, minutes=59, seconds=59)
last_quarter_start = datetime.datetime(last_quarter_end.year, last_quarter_end.month - 2, 1)
print('--- last_quarter_start = {} last_quarter_end = {}'.format(last_quarter_start, last_quarter_end))
  
# 本年第一天和最后一天
this_year_start = datetime.datetime(now.year, 1, 1)
this_year_end = datetime.datetime(now.year + 1, 1, 1) - timedelta(days=1)+ datetime.timedelta(
    hours=23, minutes=59, seconds=59)
print('--- this_year_start = {} this_year_end = {}'.format(this_year_start, this_year_end))
  
# 去年第一天和最后一天
last_year_end = this_year_start - timedelta(days=1)+ datetime.timedelta(
    hours=23, minutes=59, seconds=59)
last_year_start = datetime.datetime(last_year_end.year, 1, 1)
print('--- last_year_start = {} last_year_end = {}'.format(last_year_start, last_year_end))

　　

 

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