Run certain code every n seconds [duplicate]

Is there a way to, for example, print Hello World! every n seconds? For example, the program would go through whatever code I had, then once it had been 5 seconds (with time.sleep()) it would execute that code. I would be using this to update a file though, not print Hello World.

For example:

startrepeat("print('Hello World')", .01) # Repeats print('Hello World') ever .01 seconds

for i in range(5):
    print(i)

>> Hello World!
>> 0
>> 1
>> 2
>> Hello World!
>> 3
>> Hello World!
>> 4

import threading

def printit():
  threading.Timer(5.0, printit).start()
  print "Hello, World!"

printit()

# continue with the rest of your code

https://docs.python.org/3/library/threading.html#timer-objects

My humble take on the subject, a generalization of Alex Martelli's answer, with start() and stop() control:

from threading import Timer

class RepeatedTimer(object):
    def __init__(self, interval, function, *args, **kwargs):
        self._timer     = None
        self.interval   = interval
        self.function   = function
        self.args       = args
        self.kwargs     = kwargs
        self.is_running = False
        self.start()

    def _run(self):
        self.is_running = False
        self.start()
        self.function(*self.args, **self.kwargs)

    def start(self):
        if not self.is_running:
            self._timer = Timer(self.interval, self._run)
            self._timer.start()
            self.is_running = True

    def stop(self):
        self._timer.cancel()
        self.is_running = False

Usage:

from time import sleep

def hello(name):
    print "Hello %s!" % name

print "starting..."
rt = RepeatedTimer(1, hello, "World") # it auto-starts, no need of rt.start()
try:
    sleep(5) # your long-running job goes here...
finally:
    rt.stop() # better in a try/finally block to make sure the program ends!

Features:

Standard library only, no external dependencies
start() and stop() are safe to call multiple times even if the timer has already started/stopped
function to be called can have positional and named arguments
You can change interval anytime, it will be effective after next run. Same for args, kwargs and even function!

def update():
    import time
    while True:
        print 'Hello World!'
        time.sleep(5)

That'll run as a function. The while True: makes it run forever. You can always take it out of the function if you need.

Save yourself a schizophrenic episode and use the Advanced Python scheduler: http://pythonhosted.org/APScheduler

The code is so simple:

from apscheduler.scheduler import Scheduler

sched = Scheduler()
sched.start()

def some_job():
    print "Every 10 seconds"

sched.add_interval_job(some_job, seconds = 10)

....
sched.shutdown()

Run certain code every n seconds [duplicate]

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