Question

Need to turn x:

X = [['A', 'B', 'C'], ['A', 'B', 'D']]

Into Y:

Y = {'A': {'B': {'C','D'}}}

More specifically, I need to create a tree of folders and files from a list of absolute paths, which looks like this:

paths = ['xyz/123/file.txt', 'abc/456/otherfile.txt']

where, each path is split("/"), as per ['A', 'B', 'C'] in the pseudo example.

As this represents files and folders, obviously, on the same level (index of the array) same name strings can’t repeat.

Answer 1

X = [['A', 'B', 'C'], ['A', 'B', 'D'],['W','X'],['W','Y','Z']]
d = {}

for path in X:
    current_level = d
    for part in path:
        if part not in current_level:
            current_level[part] = {}
        current_level = current_level[part]

This leaves us with d containing {'A': {'B': {'C': {}, 'D': {}}}, 'W': {'Y': {'Z': {}}, 'X': {}}}. Any item containing an empty dictionary is either a file or an empty directory.