Here's an example codes using path module.
You first need to download it here: path.py

# make some files excutable
d = path('/usr/home/guido/bin')
for f in d.files('*.py'):
    f.chmod(0755)

# Directory walking - delete Emacs backup files
d = path(os.environ['HOME'])
for f in d.walkfiles('*~'):
    f.remove()

Using os.path is difficult. I can hardly remember how to
use which method. Need to lookup the manual every time.
This path module is much much easier to use.
I've heard it will be included in python 2.5 as well.