Transform any object into dict by recursively exploring __dict__ attribute

to_dict.py

import json


def is_iterable(obj):
    try:
        for _ in obj:
            return True
    except TypeError:
        return False


def obj_to_dict(data, do_not_iter_types=(str, bytes)):
    return (
        {
            k: obj_to_dict(v)
            for k, v in dict(vars(data)).items()
            if isinstance(k, str) and not (k.startswith("__") and k.endswith("__"))
        }
        if hasattr(data, "__dict__")
        else (
            data if isinstance(data, dict)
            else [obj_to_dict(datum) for datum in data]
            if (is_iterable(data) and not isinstance(data, do_not_iter_types))
            else repr(data)
        )
    )


def obj_to_json(data):
    return json.dumps(obj_to_dict(data), indent=2, default=str, skipkeys=True)


def rpprint(data):
    print(obj_to_json(data))


if __name__ == "__main__":
    # obj_to_dict(json)
    a = {1:1,2:2}
    rpprint(json)

At the 9th revision, it still does not support data structures having a reference to themselves.