DeserializationError when loading into a class with an Optional bson.ObjectID about jsons HOT 2 OPEN

Hi @yurirocha15 ,

You are trying to load a "half json-serialized" object; a dict that contains objects that are not json-compatible (bson.objectid.ObjectId instances).

I traced down what happened. In non-strict mode, when an object is loaded into a class of which it already is an instance (e.g. load("this is a string", str)), the loading is skipped and that instance is returned instantly. This is what happens with your data1. With data2, it compares the type ObjectId with Optional which are inequal, therefore it is not skipped. Then, before actually trying to deserialize an ObjectId, it stops as ObjectId is not a json value (one of str, int, float, bool, list, tuple, set, dict, NoneType).

Do you really need to load a "half json-serialized" object, or would it be possible in your case to just do the following?

TestData(**data2)

from jsons.

This would be possible in the example I posted but not in my real use case. I am parsing a nested dictionary into nested dataclasses; this optional parameter is in the deeper layers of the dictionary. Therefore, using the root dataclass constructor directly is not an option for me.

Is there any way to solve this using custom serializers/deserializers?

from jsons.