Pausing a called function for a few seconds

Question

I have a function F1 that loops continuously (while loop). I have set a condition, if met, calls another function F2 inside function F1. Once called, the function F2 shouldn't be called again for a few seconds, say 3 secs, even if the condition is met again within 3 seconds. But function F1 has to be looping continuously. How do I achieve it?

can you share the code you already have? is time.sleep(3) not helping you? — Axblert, Dec 27 '19 at 10:12
@Axblert time.sleep() won't help because is freezes the script. — Psytho, Dec 27 '19 at 10:14
ah interesting, it would freeze the entire script, not just the scope of the function? — Axblert, Dec 27 '19 at 10:15
Maybe you can use timers : https://stackoverflow.com/questions/17167949/how-to-use-timer-in-c — WaLinke, Dec 27 '19 at 10:35

score 4 · Answer 1 · answered Dec 27 '19 at 10:13

4

Save time when you call F2 (say time_f2). Next time the condition is met, compare now with time_f2 and call F2 only if the difference is more than 3 seconds.

answered Dec 27 '19 at 10:13

Psytho

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Scope of time_f2 is limited to F1's one instance only. Once F1 is called again, time_f2 will not have the same value as the previous run. It can be defined as Global variable. – Main Dec 27 '19 at 10:33

Main · Answer 2 · 2019-12-30T09:34:53.883

You can try something like below. I have introduced new parameters to F1. In <condition met> you will write your own conditions.

from datetime import datetime

first_time_f2_call = True
time_f2_call = datetime.now()
while True:
    time_f2_call = f1(first_time_f2_call, time_f2_call)
    first_time_f2_call = False


def f1(first_f2_call, last_f2_call_time):
    if first_f2_call:
        time_diff = datetime.now() - datetime.now()
    else:
        time_diff = datetime.now() - last_f2_call_time

    if <condition met> and time_diff.seconds > 3:
        f2()
        last_f2_call_time = datetime.now()

    .
    .
    .
    return last_f2_call_time

score 2 · Accepted Answer · answered Dec 27 '19 at 11:40

Sure there are better ways, but you can use time.time() to watch for at least 3 seconds of difference and reset a flag

import time
tf = 0
ti = 0
while 1:
    print('your_main_stuff()')
    yourcondition = True
    if yourcondition and tf==ti:
        print('do_your_stuff_once_at_3_sec()')
        count = True
        ti = time.time()
    if count:
        tf = time.time()
        if tf-ti>3:
            tf = time.time()
            ti = time.time()
            count = False

Slightly modified your code and it worked! Thank you :) – Gautham Dec 30 '19 at 07:05 — Gautham, Dec 30 '19 at 07:05

Pausing a called function for a few seconds

3 Answers3