import os, fnmatch

def locate(pattern, root=os.curdir):
    '''Locate all files matching supplied filename pattern in and below
    supplied root directory.'''
    for path, dirs, files in os.walk(os.path.abspath(root)):
        for filename in fnmatch.filter(files, pattern):
            yield os.path.join(path, filename)

http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/499305

os.walk is a very nice replacement for os.path.walk, which I never did feel comfortable with. There's one very common pattern of usage, though, which still benefits from a simple helper-function; locating all files matching a given file-name pattern within a directory tree.

Locating files throughout a directory tree

Python