How to constantly run Python script in the background on Windows?

One option is to change your script so it is intended to run continuously rather than repeatedly. Just wrap the whole thing in a while loop and add a sleep.

import time

while True:
   your_script_here
   time.sleep(300)

In order to make sure this starts up with the machine and to provide automatic restarts in the event of an exception I'd recommend making it into a Windows service using Non-Sucking Service Manager (www.nssm.cc). There are a few steps to this (see the docs) but once done your script will be just another windows service which you can start and stop from the standard services.msc utility.

I've found a solution that works:

import shutil, os, time

while True:
    for filename in os.listdir('folderToMoveFrom'):
        if filename.endswith((desired file extensions)):
            shutil.move( (folderToMoveFrom + filename), folderToMoveTo)
    time.sleep(6)

If you perform the above code without the time.sleep() function the program crashes after a new file enters the folder due to a 'file not found' error nested inside another 'file not found' error. Not sure what that's about but I'm happy with what I have so far. Only thing you need to do now is add the script to the Task Scheduler to run under Pythonw so it operates as a background process. Or instead of running the script you could run a batch file as long as you remember to add the appropriate instruction for pythonw. You only need to start the process once of course.

On Windows, you can use pythonw.exe in order to run a python script as a background process:

Python scripts (files with the extension .py) will be executed by python.exe by default. This executable opens a terminal, which stays open even if the program uses a GUI. If you do not want this to happen, use the extension .pyw which will cause the script to be executed by pythonw.exe by default (both executables are located in the top-level of your Python installation directory). This suppresses the terminal window on startup.

For example,

C:\ThanosDodd\Python3.6\pythonw.exe C:\\Python\Scripts\moveDLs.py

In order to make your script run continuously, you can use sched for event scheduling:

The sched module defines a class which implements a general purpose event scheduler

import sched
import time

event_schedule = sched.scheduler(time.time, time.sleep)

def do_something():
    print("Hello, World!")
    event_schedule.enter(30, 1, do_something, (sc,))

event_schedule.enter(30, 1, do_something, (s,))
event_schedule.run()

Now in order to kill a background process on Windows, you simply need to run:

taskkill /pid processId /f

Where processId is the ID of the process you want to kill.