Argthtjtr

From a list of lists, I would like to create a nested dictionary of which the keys would point to the next value in the sublist. In addition, I would like to count the number of times a sequence of sublist values occurred.

Example:

From a list of lists as such:

[['a', 'b', 'c'],

['a', 'c'],

['b']]

I would like to create a nested dictionary as such:

{

  'a': {

          {'b': 

                {

                'c':{}

                'count_a_b_c': 1

                }

            'count_a_b*': 1

          }, 

          {'c': {},

           'count_a_c': 1

          }

          'count_a*': 2

        },

  {

  'b':{},

  'count_b':1

  }

}

Please note that the names of the keys for counts do not matter, they were named as such for illustration.

i was curious how i would do this and came up with this:

lst = [['a', 'b', 'c'],

['a', 'c'],

['b']]



tree = {}

for branch in lst:

    count_str = 'count_*'

    last_node = branch[-1]

    cur_tree = tree

    for node in branch:

        if node == last_node:

            count_str = count_str[:-2] + f'_{node}'

        else:

            count_str = count_str[:-2] + f'_{node}_*'

        cur_tree[count_str] = cur_tree.get(count_str, 0) + 1

        cur_tree = cur_tree.setdefault(node, {})

nothing special happening here...

for your example:

import json

print(json.dumps(tree, sort_keys=True, indent=4))

produces:

{

    "a": {

        "b": {

            "c": {},

            "count_a_b_c": 1

        },

        "c": {},

        "count_a_b_*": 1,

        "count_a_c": 1

    },

    "b": {},

    "count_a_*": 2,

    "count_b": 1

}

it does not exactly reproduce what you imagine - but that is in part due to the fact that your desired result is not a valid python dictionary...

but it may be a starting point for you to solve your problem.