Question

Dear Stackoverflow Members,

I have this JSON array, and it consists of the following items (basically):

{
    {
        'Name': 'x',
        'Id': 'y',
        'Unsusedstuff' : 'unused',
        'Unsusedstuff2' : 'unused2',
        'Children': []
    },
    {   'Name' : 'xx',
        'Id': 'yy',
        'Unsusedstuff' : 'unused',
        'Unsusedstuff2' : 'unused2',
        'Children': [{
            'Name': 'xyx',
            'Id' : 'yxy',
            'Unsusedstuff' : 'unused',
            'Unsusedstuff2' : 'unused2',
            'Children: []
        }

You get the basic idea. I want to emulate this (and just grab the id and the name and the structure) in a Python-list using the following code:

names = []
def parseNames(col):
    for x in col:
        if(len(x['Children'])> 0):
            names.append({'Name' : x['Name'], 'Id' : x['Id'], 'Children' : parseNames(x['Children'])})
        else:
            return {'Name' : x['Name'], 'Id' : x['Id']}

But, it only seems to return the first ‘root’ and the first nested folder, but doesn’t loop through them all.

How would I be able to fix this?

Greetings,

Mats

Answer 1

The way I read this, you’re trying to convert this tree into a tree of nodes which only have Id, Name and Children. In that case, the way I’d think of it is as cleaning nodes.

To clean a node:

1. Create a node with the Name and Id of the original node.
2. Set the new node’s Children to be the cleaned versions of the original node’s children. (This is the recursive call.)

In code, that would be:

def clean_node(node):
    return {
        'Name': node['Name'],
        'Id': node['Id'],
        'Children': map(clean_node, node['Children']),
    }

>>> print map(clean_node, data)
[{'Name': 'x', 'Children': [], 'Id': 'y'}, {'Name': 'xx', 'Children': [{'Name': 'xyx', 'Children': [], 'Id': 'yxy'}], 'Id': 'yy'}]

I find it’s easier to break recursive problems down like this – trying to use global variables turns simple things very confusing very quickly.