Python time module: time

Time module: time
Time is a built-in module of python, which passes a series of operation time functions. Reference method:

import time; #Introduce time module

Time acquisition

• timestamp
  Each timestamp is expressed as how much time has passed since 00:00 on January 1, 1970

  nowtime=time.time()

• Visualize time
  Since the timestamp is not suitable for our observation, we can use ctime to visualize the time of the timestamp transfer behavior.

  nowtime=time.ctime()

• time tuple
  Time tuple (struct_time) is a time format that python can handle

  nowtime=time.gmtime

  Due to the division of different time zones, we will find that the time we obtain will be eight hours different from the actual time. We can obtain the local time through localtime, and the obtained time is also a time tuple structure.

  localtime=time.localtime()

  Time formatting

  >>>localtime=time.localtime()
  >>>time.strftime("%Y-%m-%d %H:%M:%S"),localtime

  Structured representation

  Format	Meaning
  %a	locale simplified day of the week name
  %A	Local full week name
  %b	Local simplified month name
  %B	Local full month name
  %c	Local corresponding date and time representation
  %d	Day of the month (01 - 31)
  %H	Hour of the day (24-hour clock, 00 - 23)
  %I	Hour number (12-hour clock, 01 - 12)
  %j	Day of the year (001 - 366)
  %m	Month (01 - 12)
  %M	Minutes (00 - 59)
  %p	The corresponding character of local am or pm
  %S	Seconds (01 - 61)
  %U	The number of weeks in the year. (Sunday 00 - 53 is the start of the week.) All days before the first Sunday are placed in week 0.
  %w	Day of the week (0 - 6, 0 is Sunday)
  %W	is basically the same as %U, except that %W starts the week on Monday.
  %x	Local corresponding date
  %X	Local response time
  %y	Year without century (00 - 99)
  %Y	Complete year
  %Z	The name of the time zone (null character if not present)
  %%	‘%’ character

  Program timing

• perf_counter()
  perf_counter() is a timing function that can return a CPU-level accurate count value in seconds. When used, two timings are required to calculate the difference to obtain the correct program running time.

  >>>start=time.ptrf_counter()
  >>>end=time.ptrf_counter()
  >>>time=end-start

  -sleep()
  sleep(s) is a sleep function. Its usage is similar to C/C++. s is the sleep time, the unit is seconds, and it can be a floating point number.

  >>>def wait():
  time.sleep(3.3)
  >>>wait()