Simple dict sucblass for making it possible to access keys as attributes

dictobject.py

from collections import defaultdict


class DictObject(dict):
    """
    Simple dict subclass for making it possible to to access keys as attributes

    This class can be used as object_hook when deserializing JSON for easy
    access to attributes of the JSON objects.

    Example::

        >>> import json
        >>> result = json.loads('{"a": 1, "b": 2}', object_hook=DictObject)
        >>> result
        DictObject({'a': 1, 'b': 2})
        >>> result.a == result['a'] == 1
        True
        >>> result.b == result['b'] == 2
        True
        >>> result.c = 3
        >>> result.c == result['c'] == 3
        True
        >>> result
        DictObject({'a': 1, 'b': 2, 'c': 3})
        >>> del result.a
        >>> result
        DictObject({'b': 2, 'c': 3})
        >>> result.a
        Traceback (most recent call last):
        ...
        AttributeError: 'DictObject' object has no attribute 'a'
        >>> del result.a
        Traceback (most recent call last):
        ...
        AttributeError: 'DictObject' object has no attribute 'a'
    """
    # We are defining empty __slots__ because we will use the keys in
    # self as attributes and we do not want the resulting object to
    # have __dict__ which will waste memory.
    __slots__ = ()

    def __getattr__(self, attr):
        try:
            return self[attr]
        except KeyError:
            raise AttributeError("'{}' object has no attribute {!r}".format(self.__class__.__name__, attr))

    def __setattr__(self, attr, val):
         self[attr] = val

    def __delattr__(self, attr):
        try:
            del self[attr]
        except KeyError:
            raise AttributeError("'{}' object has no attribute {!r}".format(self.__class__.__name__, attr))

    def __dir__(self):
        return list(sorted(set(super().__dir__()).union(self)))
    
    def __repr__(self):
        return '{}({})'.format(self.__class__.__name__, dict.__repr__(self))


class DefaultDictObject(DictObject, defaultdict):
    """
    Implements DictObject as defaultdict

    Example::

        >>> d = DefaultDictObject(list)
        >>> d
        DefaultDictObject(<class 'list'>, {})
        >>> [] == d.something == d['something']
        True
        >>> d = DefaultDictObject(list, {'a': [1, 2, 3]})
        >>> d
        DefaultDictObject(<class 'list'>, {'a': [1, 2, 3]})
        >>> [1, 2, 3] == d.a == d['a']
        True
    """
    # We are redefining __slots__ to be empty because of the same reason
    # as in DictObject - to not waste memory.
    __slots__ = ()

    def __repr__(self):
        return '{}({!r}, {})'.format(self.__class__.__name__,
                                     self.default_factory,
                                     dict.__repr__(self))


if __name__ == "__main__":
    import doctest
    doctest.testmod()