PYTHON Simple 'Unix Tree' script

unix_tree.py

import os
import sys

def getroot():
    # If the length of 'sys.argv' is longer than one, index 1 is assumed to be
    # root.
    if len(sys.argv) == 1:
        path = ''
    else:
        path = sys.argv[1]
    # If 'path' is root, it becomes 'tree_root'. If 'path' is not root, 
    # 'tree_root' becomes the current working directory. 'os.path.join'
    # concatenates a '/' onto the end of cwd.
    if os.path.isabs(path):
        tree_root = path
    else:
        tree_root = os.path.join(os.getcwd(), path)

    return tree_root

def getdirlist(path):
    # Returns all files and directories in 'path' as a ordered list of strings.
    dirlist = os.listdir(path)
    dirlist.sort()
    return dirlist

def traverse(path, prefix = '|--', s = '.\n', f = 0, d = 0):
    # Gets an ordered list of files in the cwd as strings. 
    dirlist = getdirlist(path)
    # Concatenates everything to 's' to be printed as the tree
    for num, file in enumerate(dirlist):
        lastprefix = prefix[:-3] + '`--'
        dirsize = len(dirlist)
        
        if num < dirsize - 1:
            # Prints as follows: '|-- stupid.py'
            s += '%s %s\n' % (prefix, file)
        else:
            s += '%s %s\n' % (lastprefix, file)
        # 'path2file' becomes the address to the file
        path2file = os.path.join(path, file)
        # a recursive call is ran if the file is a directory
        if os.path.isdir(path2file):
            d += 1
            if getdirlist(path2file):
                s, f, d = traverse(path2file, '|   ' + prefix, s, f, d)
        else:
            f += 1

    return s, f, d

if __name__ == '__main__':
    #root = getroot()
    root = '/home/timejr/temp/'
    tree_str, files, dirs = traverse(root)

    if dirs == 1:
        dirstring = 'directory'
    else:
        dirstring = 'directories'
    if files == 1:
        filestring = 'file'
    else:
        filestring = 'files'
    # prints the Unix tree and how many files and directories there are
    print tree_str
    print '%d %s, %d %s' % (dirs, dirstring, files, filestring)