Rename Multiple Files Using Python

Using python to rename multiple files

 import os

rootdir = r'target'

str = "08"

for filename in os.listdir(rootdir):

    if str in filename:

        filepath = os.path.join(rootdir, filename)

        newfilepath = os.path.join(rootdir, filename.replace(str, "09"))

        os.rename(filepath, newfilepath)