How would I group JSON objects by id’s to make a nested JSON in Python? The JSON is structured this way:
[{
"id": "4",
"title": "Part 4",
"children": {}
},{
"id": "4.1.",
"title": "Section 4.1. Transition Rule",
"children": {}
},
{
"id": "4.1.1.",
"title": "4.1.1. Transition, January 2014",
"children": {}
},
{
"id": "4.1.1.1.",
"title": "4.1.1.1. Transition Rule",
"children": {}
},
{
"id": "4.1.2.",
"title": "4.1.2. Transition, January 2015",
"children": {}
},
{
"id": "4.1.2.1.",
"title": "4.1.2.1. Transition Rule",
"children": {}
},
]]
The goal is to have a tree structure where each object(section) contains all its subsections going from 4 to 4.1 > 4.1.1 > 4.1.1.1.
The snippet of the required output is below:
[
{
"id":"4",
"title":"Part 4",
"children":{
{
"id":"4.1.",
"title":"Section 4.1. Transition Rule",
"children":{
{
"id":"4.1.1.",
"title":"4.1.1. Transition, January 2014",
"children":{
{
"id":"4.1.1.1.",
"title":"4.1.1.1. Transition Rule",
"children":{
}
}
}
},
{
"id":"4.1.2.",
"title":"4.1.2. Transition, January 2015",
"children":{
{
"id":"4.1.2.1.",
"title":"4.1.2.1. Transition Rule",
"children":{
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Answer
You can use recursion:
from collections import defaultdict
def get_tree(d):
_d, r = defaultdict(list), []
for i in d:
_d[i['key'][0]].append({**i, 'key':i['key'][1:]})
for b in _d.values():
j, k = [l for l in b if not l['key']], [l for l in b if l['key']]
if j:
r.extend([{**{x:y for x, y in i.items() if x != 'key'}, 'children':get_tree(k)} for i in j])
else:
r.extend(get_tree(k))
return r
data = [{'id': '4', 'title': 'Part 4', 'children': {}}, {'id': '4.1.', 'title': 'Section 4.1. Transition Rule', 'children': {}}, {'id': '4.1.1.', 'title': '4.1.1. Transition, January 2014', 'children': {}}, {'id': '4.1.1.1.', 'title': '4.1.1.1. Transition Rule', 'children': {}}, {'id': '4.1.2.', 'title': '4.1.2. Transition, January 2015', 'children': {}}, {'id': '4.1.2.1.', 'title': '4.1.2.1. Transition Rule', 'children': {}}, {'id': '4.1.3.', 'title': '4.1.3. Transition, January 2017', 'children': {}}]
import json
print(json.dumps(get_tree([{**i, 'key':[*filter(None, i['id'].split('.'))]} for i in data]), indent=4))
Output:
[
{
"id": "4",
"title": "Part 4",
"children": [
{
"id": "4.1.",
"title": "Section 4.1. Transition Rule",
"children": [
{
"id": "4.1.1.",
"title": "4.1.1. Transition, January 2014",
"children": [
{
"id": "4.1.1.1.",
"title": "4.1.1.1. Transition Rule",
"children": []
}
]
},
{
"id": "4.1.2.",
"title": "4.1.2. Transition, January 2015",
"children": [
{
"id": "4.1.2.1.",
"title": "4.1.2.1. Transition Rule",
"children": []
}
]
},
{
"id": "4.1.3.",
"title": "4.1.3. Transition, January 2017",
"children": []
}
]
}
]
}
]