Rename files (consecutively numbered)

rename-files.py

#!/usr/bin/env python
import sys, os
'''
Usage: python rename-files.py [directory] [extension] [new name base]
Example: python rename-files.py . .png frame-
'''

try:
    directory   = sys.argv[1]
    extension   = sys.argv[2]
    newNameBase = sys.argv[3]
except:
    print("Error: Missing input argument")
    print(__doc__)
    exit()

# get list of files (filtered by extension)
files = [file for file in os.listdir(directory) if file.endswith(extension)]

# get length for zero padding
zeroPaddingLength = len(str(len(files)))

# rename
for i, f in enumerate(files):
    newFileName = newNameBase + str(i).zfill(zeroPaddingLength) + extension
    os.rename(os.path.join(directory, f), os.path.join(directory, newFileName))