Python: Outward Walk

outward_walk.py

import os

def outward_walk(bottom, func, arg=None):
    '''
    Walks out of directory to the upper level directories in the path.
    Usage is very similar to os.path.walk.
    '''

    levels = bottom.split('/')
    while len(levels) > 1:
        dirname = '/'.join(levels)
        func(arg, dirname, os.listdir(dirname))
        levels.pop()
    func(arg, '/', os.listdir('/'))