Question

I have a strictly sorted list of strings:

['a',
 'b',
 'b/c',
 'b/d',
 'e',
 'f',
 'f/g',
 'f/h',
 'f/h/i',
 'f/h/i/j']

This list is similar to tree representation. So, I need to convert it to dict:

{'a': {},
 'b': {'c': {},
       'd': {}},
 'e': {},
 'f': {'g': {},
       'h': {'i': {'j': {}}}}}

As you can see, keys in this dict are parents and values are children.

UPD: I agree that empty dict is better than None

Answer 1

If you don’t insist on None as the leaf value, you can use the compact code

my_dict = lambda: defaultdict(my_dict)
d = my_dict()
for x in my_list:
    reduce(defaultdict.__getitem__, x.split("/"), d)

Admittedly, it isn’t that obvious what this code does, but it’s succinct 🙂