batch_rename.py

import os, shutil
from multiprocessing import Pool

def get_img_path(folder):
	return (os.path.join(folder, f)
		for f in os.listdir(folder)
		if 'jpg' in f)

name = 'obj'
def rename_move(filename):
	os.rename(filename[1], '{}_{}.jpg'.format(name,filename[0]))

if __name__ == '__main__':
	folder = os.getcwd()
	images = get_img_path(folder)
	img_c = list(enumerate(images, 0))
	pool = Pool()
	pool.map(rename_move, img_c)
	pool.close()
	pool.join()