python script to poll a folder continuously after a certain time interval and copy the new files to another location

Question

I want to poll a folder continuously for any new files, lets say every 1 hours and whenever it finds a new file, it copies to a specific location. I found code to find latest file and to copy to another location. How do I merge this two to get the above desired result? This also may be helpful How to get the most recent file

Answer 1

For polling, the simplest solution is time.sleep(n) which sleeps for n seconds. Your code would look something like this, then:

import time.sleep as sleep
import sys

try:
    while True:
        # code to find the latest file

        # code to copy it to another location

        sleep(3600)
except KeyboardInterrupt:
    print("Quitting the program.")
except:
    print("Unexpected error: "+sys.exc_info()[0])
    raise

(Because this loop can run forever, you should definitely wrap it in a try/except block to catch keyboard interrupts and other errors.) Cron jobs are a perfectly good option if you're only going to be on *nix platforms, of course, but this provides platform independence.

Answer 2

The periodic nature of it suggests that you can use a cron job for it. You can set a cron job to run your python script every hour. It's then the script that handles copying of the file. That is if you're on a Unix machine

crontab -e // this will open your crontab file, then add
0 * * * * /path/to/your/script.py

above will run 0 minutes past every hour

Answer 3

If you want to combine that with more tasks in the same script the sleep is not an option, in that case you could something like this:

import time
interval = 3600
lasttime = time.time()

# This is supposed to run repeatedly inside your main loop
now = time.time()
if ((lasttime - now)>interval):
  lasttime = now
  doTask()