json reference extraction in python

Question

Json is not only useful as a communication tool for APIs, but also may be used as a markup for configuring running programs as initialization.

I encountered the use of references in json schema for the purpose of reuse.

Since json schema is valid json, I had expected the python json library to have the ability to expand references.

$ cat test.json
{ 
  "template":{
    "a":"a",
    "b":"b",
    "pi":3.14
  },
  "value": { "$ref":"#/template"}
}
python -c "from json import load; fp = open(\"test.json\",\"r\"); print(load(fp))"
{'template': {'a': 'a', 'b': 'b', 'pi': 3.14}, 'value': {'$ref': '#/template'}}

What is the simplest way to expand the references in python, since python dicts cannot point to other parts of themselves (I think)?

Answer 1

The json library does not support references, but jsonref does.

jsonref is a library for automatic dereferencing of JSON Reference objects for Python (supporting Python 2.6+ and Python 3.3+).

From the docs:

from pprint import pprint
import jsonref

# An example json document
json_str = """{"real": [1, 2, 3, 4], "ref": {"$ref": "#/real"}}"""
data = jsonref.loads(json_str)
pprint(data)  # Reference is not evaluated until here
{'real': [1, 2, 3, 4], 'ref': [1, 2, 3, 4]}