jsonref 0.2

An implementation of JSON Reference for Python

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

This library lets you use a data structure with JSON reference objects, as if the references had been replaced with the referent data.

>>> 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]}

Features

• References are evaluated lazily. Nothing is dereferenced until it is used.

• Recursive references are supported, and create recursive python data structures.

References objects are actually replaced by lazy lookup proxy objects which are almost completely transparent.

>>> data = jsonref.loads('{"real": [1, 2, 3, 4], "ref": {"$ref": "#/real"}}')
>>> # You can tell it is a proxy by using the type function
>>> type(data["real"]), type(data["ref"])
(<class 'list'>, <class 'jsonref.JsonRef'>)
>>> # You have direct access to the referent data with the __subject__
>>> # attribute
>>> type(data["ref"].__subject__)
<class 'list'>
>>> # If you need to get at the reference object
>>> data["ref"].__reference__
{'$ref': '#/real'}
>>> # Other than that you can use the proxy just like the underlying object
>>> ref = data["ref"]
>>> isinstance(ref, list)
True
>>> data["real"] == ref
True
>>> ref.append(5)
>>> del ref[0]
>>> # Actions on the reference affect the real data (if it is mutable)
>>> pprint(data)
{'real': [2, 3, 4, 5], 'ref': [2, 3, 4, 5]}