给定 JSON 中的关键路径，如何访问 JSON 中的 $ref 并获取属性中的“类型”？

Question

I'm new to SO and I am really stuck on a problem I'm trying to solve at my first job. I have this sample JSON, in which, I need to find the "type" of whatever key path I send it.

For example, foo(sample_json, 'work.id') should return an "number".

Another example, foo(sample_json, 'work.composer.artist.name') should return a "string"

sample_json =  {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "title": "Schema for a recording",
      "type": "object",
      "definitions": {
        "artist": {
          "type": "object",
          "properties": {
            "id": {"type": "number"},
            "name": {"type": "string"},
            "functions": {
              "type": "array",
              "items": {"type": "string"}
            }
          },
          "required": ["id", "name", "functions"]
        }
      },
      "properties": {
        "id": {"type": "number"},
        "work": {
          "type": "object",
          "properties": {
            "id": {"type": "number"},
            "name": {"type": "string"},
            "composer": {"$ref": "#/definitions/artist"}
          }
        },
        "recording_artists": {
          "type": "array",
          "items": {"$ref": "#/definitions/artist"}
        }
      },
      "required": ["id", "work", "recording_artists"]
    }

I have just started writing the code. How do I go about it?

What would be the right way? I know this question may not get you a lot of points, but will surely help me greatly.

def foo(schema, key_path):
  key_path_list = key_path.split('.')
  if key_path_list[0] in schema['properties']:
      if '$ref' in schema['properties'][key_path_list[0]]:
        ref = schema['properties'][key_path_list[0]]['$ref']
        ref = ref.split('/')[1:]
        print(ref)
        #I get a list, #/definitions/artist I know I can use .get(), but how do I do recursively?

I get a list, How do I go to schema['definitions']['artist'] , then ['name']['type'] ? How do I go about making it recursive as well?

Note, I need to manually make this function for now.

I'm completely lost, do help me here. Thank you in advance.

Answer 1

def foo(schema, key_path):
key_path_list = key_path.split('.')
#i = len(key_path_list)
#j=0
#print(key_path_list)
for item in key_path_list:
    if item in schema:
        #print(key_path_list)
        key_path_list.remove(item)
        if key_path_list:
            key_path = '.'.join(key_path_list)
            #print(key_path)
            foo(schema[item], key_path)
        else :
            print(schema[item])
            #print(key_path)
            #print(key_path_list)
    else:
        if not key_path_list:
            print('Please give a valid key path :)',key_path)

Answer 2

import json
data_ = json.loads(sample_json)
foo(data_,"properties.recording_artists.items.$ref" )

Please make sure to open json file as above

Answer 3

from functools import reduce  # forward compatibility for Python 3
import operator

def foo(schema, key_path):
    key_path_list = key_path.split('.')
    current_dict = schema
    for key in key_path_list:
        if current_dict.get('properties') and current_dict['properties'].get(key):
            current_dict = current_dict['properties'][key]
        elif current_dict.get('$ref'):
            new_path_list = current_dict['$ref'].split('/')[1:]
            current_dict = reduce(operator.getitem, new_path_list, schema)
        else:
            print("Wrong key_path. Please provide a valid key_path")
            return
    return current_dict['type']

# key_path = 'work.id'
key_path = 'work.composer.artist.name'
foo(sample_json, key_path)

reduce is used here to traverse the schema. Using sample_json as provided above.