How to make a time sensitive loop in Python?

Question

I want to make a function that prints a statement every 2 minutes. I'm really new to Python and don't fully understand the time library. This is the code I have so far:

 from datetime import datetime
 import time                

 now = datetime.now()       

 print now.second           
 print "start"
   while True:
      print "while loop started"
    if (now % 2 == 0):     
       print "Hello"     
    else:                  
       break

How can I do this?

do you mean from a particular time or just every two minutes from when the program starts? — Padraic Cunningham, Apr 12 '15 at 16:47
@AJFarmar sorry, I messed up when putting it in the website! — Ari K., Apr 12 '15 at 17:06
@PadraicCunningham every 2 minutes from when the program starts — Ari K., Apr 12 '15 at 17:07

Anshul Goyal · Accepted Answer · 2015-04-12T17:21:31.193

5

You can use time.sleep here. Since you want a timer for 2 minutes, pass 120 (seconds) as the argument value.

Basically, this translates into something like below:

while True:
    time.sleep(120)
    print "Hello"

This will print "Hello" every 2 minutes.

Note that time.sleep is not entirely accurate, and may be off by a small but arbitrary amount of time because of OS scheduling of other processes etc and execution of the code itself.

edited Apr 12 '15 at 17:21

answered Apr 12 '15 at 16:44

Anshul Goyal

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Keep in mind that ```time.sleep()``` is not exact, it can be a few seconds off. – pzp Apr 12 '15 at 17:19
@pzp Have added a note to that effect, thanks for pointing out :) – Anshul Goyal Apr 12 '15 at 17:21

score 2 · Answer 2 · edited May 23 '17 at 12:21

2

Use the sched module

import sched, time
s = sched.scheduler(time.time, time.sleep)
def do_something(sc): 
    print "Doing stuff..."
    # do your stuff
    sc.enter(60, 1, do_something, (sc,))

s.enter(60, 1, do_something, (s,))
s.run()

take a look here.

edited May 23 '17 at 12:21

Community

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1

answered Apr 12 '15 at 16:46

Avinash Kr Mallik

162
5

How to make a time sensitive loop in Python?

2 Answers2