如何在Python中从父/子层次结构的JSON中检索数据？

Question

我有一个调用API的请求，返回以下响应。由于所有子节点也可以是父节点，因此我很难处理并访问其中的所有子节点。

响应以以下层次结构呈现：

[
{
   "id": 459029874,
   "name": "Data",
   "children": []
},
{
  "id":762606928,
  "name":"Top 25 KPIs",
  "children":[
    {
      "id":97002306,
      "name":"KPI Definition",
      "children":[]
    },
    {
      "id":1178185669,
      "name":"DEU",
      "children":[
        {
          "id":146196511,
          "name":"DEU Development Path",
          "children":[]
        }
      ]
    }
  ]
}]

我正在尝试获得以下结果，并将其放入数据框中：

{"id": 459029874, "name": "Data", "parent_id": ""},
{"id": 762606928, "name": "Top 25 KPIs", "parent_id": ""},
{"id": 97002306, "name": "KPI Definition", "parent_id": "762606928"},
{"id": 1178185669, "name": "DEU", "parent_id": "762606928"},
{"id": 146196511, "name": "DEU Development Path", "parent_id": "1178185669"}

and so forth...

- Rani Nehme

Answer 1

对于这种问题，创建一个生成器很方便，它可以yield结果，然后递归地yields from子项，将子项传回生成器。这样可以得到非常简洁的解决方案：

def flatten(l, parent = ''):
    for item in l:
        yield {'id': item['id'], 'name': item['name'], "parent_id": parent }
        yield from flatten(item['children'], item['id'])

list(flatten(data))

结果：

[{'id': 459029874, 'name': 'Data', 'parent_id': ''},
 {'id': 762606928, 'name': 'Top 25 KPIs', 'parent_id': ''},
 {'id': 97002306, 'name': 'KPI Definition', 'parent_id': 762606928},
 {'id': 1178185669, 'name': 'DEU', 'parent_id': 762606928},
 {'id': 146196511, 'name': 'DEU Development Path', 'parent_id': 1178185669}]

- Mark