A script that uses `feh` to randomly set the desktop background, changing it every 5 minutes, and not repeating any image twice.

randomize_background.py

#  Calls Feh, puts a randomized image on the background, and changes
# the image every 5 minutes.

import os
import glob
import subprocess
import time
import random

images = glob.glob('images/*')

for image in images:
	print image

first = images[0]

delay = 5 #5 minutes.

while True:
	#randomize the order. 
	#Ensure that we don't have the same first element as the last element.
	while first== images[0]:
		random.shuffle(images)
	
	for image in images:
		feh = subprocess.Popen(['feh', '--bg-fill', image])
		time.sleep(delay * 60)

		#record the last image.
		first = image
		
		#be a nice guy.
		feh.terminate()
	random.shuffle(images)

Thanks man!