anjianshi / json_encode_manager

JSON encode helper

JSON encode manager

Python's default json encoder was difficult to extend.

Use this, you can simply register custom encoder, to handle the data types that default json encoder can't encode.

Usage：

json_encode_manager = JSONEncodeManager()
json_encode_manager.register(some_encoder, some_python_type)
...
json.dumps(data, default=json_encode_manager)

For JSONEncodeManager, there are two kinds of encoder:

The first one was specialized.

It can only encode object instance of one specific type or it's subtype.

The manager will call it only if the type of data matches its register type.

The other one was generalized, called common_encoder.

A common_encoder can encode multiple types of data (eg. tuple and list).

JSONEncodeManager will pass any type of data to these encoder.

The encoder should raise a CantEncodeObjException exception, if it think this value shouldn't handle by itself. System will catch this exception, and pass data to next encoder.

specialized encoder has higher priority than common_encoder.

System has already define some encoders, in _predefined_json_encoders and _predefined_common_json_encoders. These encoders will be registered automatically, and has lowest priority of it's kind.