Quick script to add a suffix to all images in a folder:

imageRename.py

# example: python "D:\Users\rahul\Documents\Python Scripts\image rename\imageRename.py" "D:\Users\rahul\Documents\Python Scripts\image rename\test_images" "blah"
# imageX.jpg --> imageX_blah.jpg

import os
import argparse

parser = argparse.ArgumentParser()
parser.add_argument("dir")
parser.add_argument("suffix")
args = parser.parse_args()
print(args.dir)
print(args.suffix)

answer = input("rename files in: "+args.dir+" with suffix: "+args.suffix+" are you sure? Y/N: ")

if answer.upper() != "Y":
  exit()

print("Continuing")
for filename in os.listdir(args.dir):
  src = args.dir + "\\" + filename
  dst = args.dir + "\\" + filename.split(".")[0] + "_" + args.suffix + "." + filename.split(".")[1]
  os.rename(src, dst)