delay a task until certain time

Question

What I want to do in a python script is sleep a number of seconds until the required time is reached. IE: if runAt setting is 15:20 and current time is 10:20, how can I wor

Answer 1

Think you can also use the following code:

from datetime import datetime, time
from time import sleep

def act(x):
    return x+10

def wait_start(runTime, action):
    startTime = time(*(map(int, runTime.split(':'))))
    while startTime > datetime.today().time(): # you can add here any additional variable to break loop if necessary
        sleep(1)# you can change 1 sec interval to any other
    return action

wait_start('15:20', lambda: act(100))

Answer 2

Here's a solution that uses the Arrow module:

def wait_until(specified_dt: arrow.Arrow) -> None:
"""Stay in a loop until the specified date and time."""
# Initially check every 10 seconds.
refresh = 10
current_dt = arrow.utcnow()

while current_dt < specified_dt:
    # Check every millisecond if close to the specified time.
    current_dt = arrow.utcnow()
    if (specified_dt - current_dt).seconds < 11:
        refresh = .001

    time.sleep(refresh)

Answer 3

Instead of using the function sleep(X), you can also use to a Timer

It depends on what you're planning to do.

Answer 4

Using both arrow and pause:

maintenance = arrow.now()
EndAt = maintenance.replace(hour = 17, minute = 6, second = 0)
print(maintenance,': Maintenance in progress. Pausing until :',EndAt)
pause.until(EndAt.naive)

Answer 5

If you subtract one datetime object from another you get a timedelta object, which has a seconds property, so you can do:

t1 = datetime.datetime.now()

# other stuff here
t2 = datetime.datetime.now()
delta = t2 - t1
if delta.seconds > WAIT:
    # do stuff
else:
    # sleep for a bit

As an aside, you might want to use cron for tasks that are supposed to run at specific times.

Answer 6

Using timedelta object is the way to go. Below is the example that worked for me and can easily be adjusted to any other time:

import datetime, time
today = datetime.datetime.now()

sleep = (datetime.datetime(today.year, today.month, today.day, 15, 20, 0) - today).seconds
print('Waiting for ' + str(datetime.timedelta(seconds=sleep)))
time.sleep(sleep)

Take into consideration that if 15:20 has already passed, this substraction will still work and will wait till the next occurrence of 15:20, because in such situations timedelta returns a negative number of days. It's 16:15 as I'm running my code:

print(datetime.datetime(today.year, today.month, today.day, 15, 20, 0) - today)
>>>-1 day, 23:05:00.176033