HGI JSON

A Python 3 library for easily JSON encoding/decoding complex class-based Python models, using an arbitrarily complex (but easy to write!) mapping schema.

Features

• Ability to create serializers and deserializers for complex class-based models using a mapping schema defined in Python.
• Works seamlessly with Python's in-built json.dumps and json.loads serialization methods - does not require the use of exotic convert_to_json/convert_from_json methods.
• Python models are not be coupled to the serialization process - models do not have to inherit from a particular superclass or implement an interface with a to_json (or similar) method.
• JSON representations produced are not coupled to the Python model - an arbitrary mapping between the JSON and the model can be defined.
• Simple to define serialization of subclasses, based on how superclasses are serialized.
• Pure Python 3 - no DSL, XML or similar required to describe mappings, not using outdated Python 2.
• Well tested.

Overview

Basic Steps

1. Define schema for mapping an object to and/or from JSON representation using a list of JsonPropertyMapping definitions.
2. Use MappingJSONEncoderClassBuilder with the mappings to build a subclass of JSONEncode for serializing instances of a specific type. Similar with decode.
3. Use created encoder class with Python's in-built json.dumps via the cls parameter. Similar with decoder.

Defining Encoders/Decoders

Encoders and decoders are generated based on a defined JSON <-> Model mapping. A mapping can be written that allows complex classes, such as that below, to be mapped to and from any JSON representation:

classCustomClass(SupportFor, MultipleInheritance):
self__init__(self, support_for_constructor_parameters):
self.support_for_all_types_of_properties=""self.including_sets=set()
self.and_lists=list()
self.and_dictionaries=dict()
self.and_complex_properties=ComplexClass()
self.and_nested_objects_of_the_same_type=CustomClass()
self.and_properties_not_in_json_if_none=Noneselfsupport_for_setters(self, value):
"""..."""selfsupport_for_getters(self):
"""..."""CustomClassJSONEncoder=MappingJSONEncoderClassBuilder(...).build() # type: JSONEncoderCustomClassJSONDecoder=MappingJSONDecoderClassBuilder(...).build() # type: JSONDecodercustom_class_as_json=json.dumps(custom_class, cls=CustomClassJSONEncoder) # type: strcustom_class=json.loads("<custom_class_as_json>", cls=CustomClassJSONDecoder) # type: CustomClass

Documentation

For more details, including information on how to setup and use the library, please view the documentation on ReadTheDocs or read it from /docs.