fork download
copy 
  1. def nest_list(L):
  2.     idx = {}
  3.     children = []
  4.     root = []
  5.     # first pass: index items by id
  6.     # if the item has no parents, put it in the 'root' list
  7.     # otherwise add it to the 'children' list which we will
  8.     # process in a second pass
  9.     for item in L:
  10.         idx[item['id']] = item
  11.         if 'parent' in item:
  12.             children.append(item)
  13.         else:
  14.             root.append(item)
  15.  
  16.     # second pass: find the parents of our children
  17.     for child in children:
  18.         parent = idx[child['parent']]
  19.         del child['parent']
  20.         try:
  21.             # retrieve the list of children for this
  22.             # parent
  23.             childlist = parent['children']
  24.         except KeyError:
  25.             # this item has received no children so far
  26.             # so we need to make a 'children' key and list
  27.             # for it.
  28.             parent['children'] = childlist = []
  29.         # append this child to the parent's list of children
  30.         childlist.append(child)
  31.  
  32.     #all done: return new root list
  33.     return root
  34.  
  35. oldlist = [{
  36.   "name":"Folder 2",
  37.   "id":"zRDg",
  38.   "parent":"OY00",
  39.   "type":"folder"
  40. },
  41. {
  42.   "name":"Folder 1",
  43.   "id":"OY00",
  44.   "type":"folder"
  45. },
  46. {
  47.   "name":"Folder 2",
  48.   "id":"ZDE1",
  49.   "type":"folder"
  50. },
  51. {
  52.   "name":"Folder 4",
  53.   "id":"aaaa",
  54.   "parent":"zRDg",   
  55.   "type":"folder"
  56. },
  57. {
  58.   "name":"DX00025.jpg",
  59.   "id":"9Xdd",
  60.   "parent":"OY00",
  61.   "type":"jpeg"
  62. }]
  63.  
  64. from pprint import pprint
  65. newlist = nest_list(oldlist)
  66. from operator import itemgetter
  67. sar = sorted(newlist,key=itemgetter('type'))
  68. pprint(newlist)
Success #stdin #stdout 0.02s 7844KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
[{'children': [{'children': [{'id': 'aaaa',
                              'name': 'Folder 4',
                              'type': 'folder'}],
                'id': 'zRDg',
                'name': 'Folder 2',
                'type': 'folder'},
               {'id': '9Xdd', 'name': 'DX00025.jpg', 'type': 'jpeg'}],
  'id': 'OY00',
  'name': 'Folder 1',
  'type': 'folder'},
 {'id': 'ZDE1', 'name': 'Folder 2', 'type': 'folder'}]
https://ideone.com/fkgYGx
language:
Python (cpython 2.7.16)
created:
11 years ago
visibility:
secret

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!