Print filesystem directory structure using trie datastructure

trie_filesystem.py

'''
Coding Problem Statement
Given a list of file paths (e.g. as output by grep), pretty print all the paths in a tree-like format. 
Write your code as the prettyPrint function (do not assume the input is sorted):

String[] prettyPrint(String[] files);

Example Input:
/a/b/c/d
/b/b/f
/foo/bar
/a/c/m
/a/b/f

Example Output:
Red Sox : Yankees 24th Feb 2000
/a
  /b
    /c
      /d (Re: Socks, Yankess 25 Feb 2000) (RedSocks: 24th )
      /x ()
    /f
  /c/m
/b/b/f
/foo/bar

Note:

If a directory has multiple sub-directories, each sub-directory sub-tree should appear on a new line
If a directory has only one sub-directory, it should appear on the same line as the parent directory
'''


# Enter your code here. Read input from STDIN. Print output to STDOUT

class Trie(object):
    def __init__(self):
        self.nodes = dict()
        self.end = False
    
def add(home, path):
    if len(path) <= 0:
        return
    aux = home
    path = path.split('/')[1:]
    for i, d in enumerate(path):
        if aux.nodes.get(d, None) is not None:
            aux = aux.nodes.get(d)
        else:
            aux.nodes[d] = Trie()
            aux = aux.nodes[d]
    aux.end = True
    return home

def show(home, padding = 0):
    assert home is not None
    
    for k, v in home.nodes.items():
        remaining = len(v.nodes)
        if remaining == 0:
            # end flag
            print((' ' * padding) + '/' + k)
            show(v, 0)
        else:
            print((' ' * padding) + '/' + k, end = ' ' if remaining == 1 else '\n')
            show(v, padding+1)

def main():
    home = Trie()
    home = add(home, '/a/b/c/d')
    home = add(home, '/a/c/m')
    home = add(home, '/foo/bar')
    home = add(home, '/a/b/f')
    
    show(home)
    
main()