Sorting JSON object(s) into a Hierarchy

Question

I need to sort out a JSON array into a Hierarchy, here my JSON file, it's never ordered but follow structure:

{
  "name":"Folder 2",
  "id":"zRDg",
  "parent":"OY00",
  "type":"folder"
},
{
  "name":"Folder 1",
  "id":"OY00",
  "type":"folder"
},
{
  "name":"Folder 3",
  "id":"ZDE1",
  "type":"folder"
},
{
  "name":"DX00025.jpg",
  "id":"9Xdd",
  "parent":"OY00",
  "type":"jpeg"
}

Into this JSON file, the structure is like this:

{
  "name":"Folder 1",
  "id":"OY00",
  "type":"folder",
  "children": [{
    "name":"Folder 2",
    "id":"zRDg",
    "type":"folder"
    },
    {
    "name":"DX00025.jpg",
    "id":"9Xdd",
    "type":"jpeg"
  }]
},
{
    "name":"Folder 3",
    "id":"ZDE1",
    "type":"folder"
}

I can't really figure it out, as i'm new to python, my start(wrong):

for index,item in result:
    if item['parent']:
        for item2 in result:
            if item2['id'] == item['parent']:
                item['children'] = item2
                brake 

This is ok, but the problem is it not correct python, folder1/folder2/folder3/ wont work for this, i need a recursive function. I should also include this structure changes, it can be folder withing folder and files withing folder/folders any combination.

Answer 1

myJson = [
    {
      "name":"Folder 2",
      "id":"zRDg",
      "parent":"OY00",
      "type":"folder"
    },
    {
      "name":"Folder 1",
      "id":"OY00",
      "type":"folder"
    },
    {
      "name":"Folder 3",
      "id":"ZDE1",
      "type":"folder"
    },
    {
      "name":"DX00025.jpg",
      "id":"9Xdd",
      "parent":"OY00",
      "type":"jpeg"
    }
]

#this creates a dictionary that maps id names to JSON items.
#ex. itemsKeyedById["9Xdd"] gives the jpg item with id "9Xdd"
itemsKeyedById = {i["id"]: i for i in myJson}

#iterate through each item in the `myJson` list.
for item in myJson:
    #does the item have a parent?
    if "parent" in item:
        #get the parent item
        parent = itemsKeyedById[item["parent"]]
        #if the parent item doesn't have a "children" member, 
        #we must create one.
        if "children" not in parent:
            parent["children"] = []
        #add the item to its parent's "children" list.
        parent["children"].append(item)

#filter out any item that has a parent.
#They don't need to appear at the top level, 
#since they will appear underneath another item elsewhere.
topLevelItems = [item for item in myJson if "parent" not in item]
print topLevelItems

Output (with indentation added by me):

[
    {
        'name': 'Folder 1', 
        'id': 'OY00',
        'type': 'folder',
        'children': [
            {
                'name': 'Folder 2', 
                'id': 'zRDg',
                'parent': 'OY00', 
                'type': 'folder'
            }, 
            {
                'name': 'DX00025.jpg', 
                'id': '9Xdd',
                'parent': 'OY00', 
                'type': 'jpeg' 
            }
        ]
    }, 
    {
        'name': 'Folder 3', 
        'id': 'ZDE1',
        'type': 'folder'
    }
 ]

It also works with items that are nested more than one deep. Example input:

myJson = [
    {
        "name":"TopLevel folder",
        "id":"0",
        "type":"folder",
    },
    {
        "name":"MidLevel folder",
        "id":"1",
        "type":"folder",
        "parent":"0"
    },
    {
        "name":"Bottom Level folder",
        "id":"2",
        "type":"folder",
        "parent":"1"
    },
    {
        "name":"Vacation Picture",
        "id":"3",
        "type":"jpg",
        "parent":"2"
    },
]

Output:

[
    {
        'type': 'folder', 
        'name': 'TopLevel folder', 
        'id': '0',
        'children': [
            {
                'type': 'folder', 
                'name': 'MidLevel folder', 
                'parent': '0', 
                'id': '1',
                'children': [
                    {
                        'type': 'folder', 
                        'name': 'Bottom Level folder', 
                        'parent': '1', 
                        'id': '2',
                        'children': [
                            {
                                'type': 'jpg', 
                                'name': 'Vacation Picture', 
                                'parent': '2', 
                                'id': '3'
                            }
                        ] 
                    }
                ]
            }
        ]
    }
]