Make a tree structure from a path name

Question

This might be very simple, but I'm not sure what to do here. In Python, I want to go through a list like:

full_list = ["A/A/A", "A/A/B", "B/B/B", "A/C/B"]

and get a dictionary with a kind of tree structure based on these labels, like this:

dictionary = {"A:{"A":["A", "B"], "C":["B"]},"B":{"B":["B]}} 

but I'm not sure how to do it. I realize that I need some nested for loops. I know about the split() function in Python.

Answer 1

You can use recursion with collections.defaultdict:

from collections import defaultdict
def to_tree(data):
   d = defaultdict(list)
   for a, *b in data:
      d[a].append(b)
   return {a:[i for [i] in b] if all(len(i) == 1 for i in b) else to_tree(b)  
           for a, b in d.items()}

full_list = ["A/A/A", "A/A/B", "B/B/B", "A/C/B"]
result = to_tree([i.split('/') for i in full_list])

Output:

{'A': {'A': ['A', 'B'], 'C': ['B']}, 'B': {'B': ['B']}}