ungron but preserve the ordering of object keys

ungron.py

#!/usr/bin/env python3
class gron:
    def __init__(self,name="json",val=None):
        if isinstance(val, dict):
            my_dict = val
        else:
            my_dict = dict()
        if isinstance(val, list):
            my_list = val
        else:
            my_list = list()
        object.__setattr__(self, '_gron__dict', my_dict)
        object.__setattr__(self, '_gron__list', my_list)

    def __str__(self):
        import json as _json
        return _json.dumps(self.__dict, default = lambda x: x.__json())

    def __json(self):
        if len(self.__list):
            return self.__list
        else:
            return self.__dict

    def __setitem__(self, item, val):
        if isinstance(item, int):
            l = self.__list
            while len(l) <= item:
                l.append(None)

            l[item] = val
        else:
            self.__dict[item] = valddk

    def __setattr__(self, key, val):
        if isinstance(val, (dict,list)):
            val = gron(key, val)
        self.__dict[key] = val
        return

    def __getattr__(self, key):
        if key in self.__dict:
            return self.__dict[key]
        else:
            self.__dict[key] = gron(key)
            return self.__dict[key]

if __name__ == '__main__':
    import sys
    json = gron()
    for line in sys.stdin:
        exec(line, None, {"json": json})
    print(json)