Rename multiple files at once with list of original file names and list of corresponding resulting file names (for easy renaming using a text editor like Sublime Text)

batchrename.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

import os       # for getting files from directory
import sys      # for accessing command line arguments

# Command line arguments
assert len(sys.argv)<4, "batchrename takes at most 1 command line argument\n"+\
                        "Use: python batchrename.py [folder_name]"

if len(sys.argv) == 1:
    folder_name = "."    # Looks in 'saves/' folder from 'scripts/' folder
    print "Use: python batchrename.py [folder_name]"
    print "Using default path: . (current folder)"
elif len(sys.argv) == 2:
    folder_name = sys.argv[1]   # First command line argument is folder

# translation table (TODO make better)
in_list  = ['file1.txt','file2.txt','file3.txt']
out_list = ['textfile_1.txt','textfile_2.txt','textfile_3.txt']

# make sure slash at end of folder name
os.path.join(folder_name, '')

# get every WAV file in folder
files_list = os.listdir(folder_name)
for f in files_list: # iterate over all files in files_list
    if f.endswith(".txt"): # check if TXT file (optional)
        if f in in_list:
            print f + ' becomes ' + out_list[in_list.index(f)] # DEBUG
            os.rename(folder_name+f, folder_name+out_list[in_list.index(f)])