https://stackoverflow.com/a/23689767/89391 / How to use a dot “.” to access members of dictionary?

23689767.py

class dotdict(dict):
    """
    A dictionary supporting dot notation.
    """
    __getattr__ = dict.get
    __setattr__ = dict.__setitem__
    __delattr__ = dict.__delitem__

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        for k, v in self.items():
            if isinstance(v, dict):
                self[k] = dotdict(v)

    def lookup(self, dotkey):
        """
        Lookup value in a nested structure with a single key, e.g. "a.b.c"
        """
        path = list(reversed(dotkey.split(".")))
        v = self
        while path:
            key = path.pop()
            if isinstance(v, dict):
                v = v[key]
            elif isinstance(v, list):
                v = v[int(key)]
            else:
                raise KeyError(key)
        return v

if __name__ == '__main__':
     dd = dotdict({"a": 1, "b": {"c": "# it works", "d": [1, 2, {"e": 123}]}})
     print(dd.b.c)
     print("#", isinstance(dd, dict))
     print("#", dd.lookup("b.d"))
     # it works
     # True
     # [1, 2, {'e': 123}]

41274937.py

from collections import defaultdict

class AttributeDict(defaultdict):
    def __init__(self):
        super(AttributeDict, self).__init__(AttributeDict)

    def __getattr__(self, key):
        try:
            return self[key]
        except KeyError:
            raise AttributeError(key)

    def __setattr__(self, key, value):
        self[key] = value

if __name__ == '__main__':
     print(AttributeDict({"a": 1, "b": {"c": "# it works"}}).b.c)

     # Traceback (most recent call last):
     #   File "41274937.py", line 18, in <module>
     #     print(AttributeDict({"a": 1, "b": {"c": "# it works"}}).b.c)
     # TypeError: __init__() takes 1 positional argument but 2 were given