time、datetime

time()

python time module

• Timestamp:
  • To see the computer, 1970-01-01 00:00:00 to the current time, in seconds calculated
• Formatting time (Format String):
  • Posters, and returns the string of time "2019-11-16 14:20:42"
• Time Object Format (struct_time):
  • It returns a tuple, 9-tuple values
    • Year, month, day, hour, minute, second, day of the week, the first day of the year, daylight saving time

1, timestamp ( time.time())

print(time.time())
#1573885583.36139

2, acquisition time format ( time.strftime())

print(time.strftime('%Y-%m-%d %H:%M:%S'))       #%X == %H:%M:%S
2019-11-16 14:27:43

3, target acquisition time ( time.locatime())

t = time.localtime()
print(t.tm_year)
print(t.tm_mon)
print(t.tm_mday)
2019
11
16

strftime()不带参数默认当前时间
print(time.strftime('%Y-%m-%d %H:%M:%S', time.localtime()))
#2019-11-16 14:39:43

print( time.strptime('2019-01-01', '%Y-%m-%d'))
#time.struct_time(tm_year=2019, tm_mon=1, tm_mday=1, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=1, tm_yday=1, tm_isdst=-1)

• measure time:perf_counter()
• Generation time:sleep()

function	description
perf_counter()	CPU returns several times a precise time count value in seconds; starting point because the value of this uncertain terms, the difference between successive calls makes sense

start_time = time.perf_counter()        #精确开始时间
end_time = time.perf_counter()          #精确结束时间
restime = end_time - start_time

function	description
sleep(s)	s proposed sleep time, in seconds, may be a float

datetime()

Mainly used for date and time calculation

Get the current date

import datetime
print(datetime.date.today())
#2019-11-16

Minutes obtain the current date

import datetime
print(datetime.datetime.today())
#2019-11-16 14:49:02.755061

t = datetime.datetime.today()
print(t.year)
print(t.month)
#2019
#11

print(datetime.datetime.now())      #北京时间
print(datetime.datetime.utcnow())   #格林威治
#2019-11-16 14:52:58.447166
#2019-11-16 06:52:58.447166

Calculate date and time

Date Date Time Time = "+" or "-" Time Object

Target = Date Time Time "+" or "-" Date Time

datetime.timedelta(day=7)Time Object

current_time = datetime.datetime.now()      #获取现在时间
print(current_time)

time_obj = datetime.timedelta(days=7)       #时间对象，获取7天时间
print(time_obj)

later_time = current_time + time_obj        #获取7天后的时间，加上7天
print(later_time)

before = current_time - time_obj            #获取7天之前的时间，减上7天
print(before)