rename a filename prior to extension for multiple files in a given directory

rename.py

''usage: python rename.py <folder> <suffix>

import sys, os

path = sys.argv[1] 
suffix = sys.argv[2] 
for filename in os.listdir(path):
    os.rename(os.path.join(path,filename), os.path.join(path, os.path.splitext(filename)[0] + '_' + suffix +'.jpg'))