sdjson 0.2.0

Custom JSON Encoder for Python utilising functools.singledispatch to support custom encoders for both Python's built-in classes and user-created classes, without as much legwork.

Custom JSON Encoder for Python utilising functools.singledispatch to support custom encoders for both Python’s built-in classes and user-created classes, without as much legwork.

Based on https://treyhunner.com/2013/09/singledispatch-json-serializer/ and Python’s json module.

Usage

Creating and registering a custom encoder is as easy as:

>>> import sdjson
>>>
>>> @sdjson.dump.register(MyClass)
>>> def encode_myclass(obj):
...     return dict(obj)
>>>

In this case, MyClass can be made JSON-serializable simply by calling dict() on it. If your class requires more complicated logic to make it JSON-serializable, do that here.

Then, to dump the object to a string:

>>> class_instance = MyClass()
>>> print(sdjson.dumps(class_instance))
'{"menu": ["egg and bacon", "egg sausage and bacon", "egg and spam", "egg bacon and spam"],
"today\'s special": "Lobster Thermidor au Crevette with a Mornay sauce served in a Provencale
manner with shallots and aubergines garnished with truffle pate, brandy and with a fried egg
on top and spam."}'
>>>

Or to dump to a file:

>>> with open("spam.json", "w") as fp:
...     sdjson.dumps(class_instance, fp)
...
>>>

sdjson also provides access to load, loads, JSONDecoder, JSONDecodeError, and JSONEncoder from the json module, allowing you to use sdjson as a drop-in replacement for json.

If you wish to dump an object without using the custom encoders, you can pass a different JSONEncoder subclass, or indeed JSONEncoder itself to get the stock functionality.

>>> sdjson.dumps(class_instance, cls=sdjson.JSONEncoder)
>>>

Note: This module does not currently support custom decoders, but might in the future.

TODO

1. Write tests with pytest. Add appropriate sections to .travis.yml and setup.py