Batch Renaming of Files in a Directory

I prefer writing small one liners for each replace I have to do instead of making a more generic and complex code. E.g.:

This replaces all underscores with hyphens in any non-hidden file in the current directory

import os
[os.rename(f, f.replace('_', '-')) for f in os.listdir('.') if not f.startswith('.')]

Such renaming is quite easy, for example with os and glob modules:

import glob, os

def rename(dir, pattern, titlePattern):
    for pathAndFilename in glob.iglob(os.path.join(dir, pattern)):
        title, ext = os.path.splitext(os.path.basename(pathAndFilename))
        os.rename(pathAndFilename, 
                  os.path.join(dir, titlePattern % title + ext))

You could then use it in your example like this:

rename(r'c:\temp\xx', r'*.doc', r'new(%s)')

The above example will convert all *.doc files in c:\temp\xx dir to new(%s).doc, where %s is the previous base name of the file (without extension).