Map dict to object attributes in Python

dict_obj_mapping.py

class DictObjMap(dict):
    """
    Converts dict to object attributes for easier value fetching
    It supports fetching nested dict and list value like `obj.array[0].item`
    Invalid list index and non-existing key will throw out IndexError and KeyError like native list and dict
    Can be migrated to dataclasses once Python is upgraded to >=3.7

    Side effect:
    Namespace of builtin dict method attributes is overridden with config keys, only other than get().
    Use dict() when calling dict methods, like `dict(obj.array[0].item).items()`
    """
    def __init__(self, *args, **kwargs):
        super(DictObjMap, self).__init__(*args, **kwargs)
        for arg in args:
            if isinstance(arg, dict):
                for k, v in arg.items():
                    if isinstance(v, dict):
                        v = DictObjMap(v)
                    elif isinstance(v, list):
                        self.__convert(v)
                    self[k] = v

        if kwargs:
            for k, v in kwargs.items():
                if isinstance(v, dict):
                    v = DictObjMap(v)
                elif isinstance(v, list):
                    self.__convert(v)
                self[k] = v

    def __convert(self, v):
        for elem in range(0, len(v)):
            if isinstance(v[elem], dict):
                v[elem] = DictObjMap(v[elem])
            elif isinstance(v[elem], list):
                self.__convert(v[elem])

    def __getattr__(self, attr):
        """
        config.does_not_exist raises error and hasattr(config, 'key_not_exists') returns False
        Change to return self.get(attr) if returning None is preferred
        """
        try:
            return self[attr]
        except KeyError:
            classname = type(self).__name__
            msg = f'{classname!r} object has no attribute {attr!r}'
            raise AttributeError(msg)

    def __setattr__(self, key, value):
        self.__setitem__(key, value)

    def __setitem__(self, key, value):
        super(DictObjMap, self).__setitem__(key, value)
        self.__dict__.update({key: value})

    def __delattr__(self, item):
        self.__delitem__(item)

    def __delitem__(self, key):
        super(DictObjMap, self).__delitem__(key)
        del self.__dict__[key]