Repeating process after elapsed time

Question

I'm trying to repeat an event every so often (doesn't matter how long, say 60 seconds) in python but I'm having some trouble. This is what I have and it should work (I thought) but it isn't:

def timedMessages():

    time_elapsed = time.time() - start_time

    if time_elapsed > 60:
        sendMessage("test")
        start_time = time.time()
        time_elapsed = 0
    else:
        time_elapsed = time.time() - start_time

start_time = time.time()

The timedMessages() function is called inside a while loop else where and start_time is set at time.time() when the program is launched. The problem occurs because my local start_time is set as a local variable again inside the timeMessages function. I'm not sure if I'm doing it wrong logically or I'm just missing something small.

you could just in-line this code in the while loop that way you’re not messing yourself up with closing over variables in different scopes.. if i wasn’t on my phone i would code up something for you, perhaps using a generator. or use the `sleep` method as the other guy suggested. — mad.meesh, Jan 05 '18 at 19:58
Possible duplicate of [What is the best way to repeatedly execute a function every x seconds in Python?](https://stackoverflow.com/questions/474528/what-is-the-best-way-to-repeatedly-execute-a-function-every-x-seconds-in-python) — wwii, Jan 05 '18 at 20:55
Also .. [Schedule a repeating event in Python 3](https://stackoverflow.com/q/2398661/2823755) — wwii, Jan 05 '18 at 20:58
I can't use time.sleep() because there are other actions that need to run at the same time — Droid, Jan 05 '18 at 22:39

score 0 · Answer 1 · answered Jan 05 '18 at 20:01

The most basic solution would be something like

while True:
    send_message()
    time.sleep(60)

If send_message() takes a while and you want more accurate timing, you could do something like

while True:
    start_time = time.time()
    send_message()
    elapsed_time = time.time() - start_time

    time.sleep(60 - elapsed_time)

That version tries to actually run it every 60 seconds by subtracting the execution time of send_message() from the sleep, so that it starts executing every 60 seconds.

If you want very accurate timing, you're going to need a more advanced technique.

Repeating process after elapsed time

1 Answers1