dotdictify.py

# turn dict into an object that allows access to nested keys via dot notation
# from http://stackoverflow.com/questions/3797957/python-easily-access-deeply-nested-dict-get-and-set
# made three modifications:
#   --added `get()` method
#   --added `if not dict.__contains__...` to `__contains__()`
#   --can now accept None as key
# JHO:
#   --updated prints and Exceptions to be python3 friendly
# https://gist.github.com/einnocent/8854896
class dotdictify(dict):
    def __init__(self, value=None):
        if value is None:
            pass
        elif isinstance(value, dict):
            for key in value:
                print(key)
                self.__setitem__(key, value[key])
        else:
            raise TypeError('expected dict')

    def __setitem__(self, key, value):
        if key is not None and '.' in key:
            my_key, rest_of_key = key.split('.', 1)
            target = self.setdefault(my_key, dotdictify())
            if not isinstance(target, dotdictify):
                raise KeyError('cannot set "{0}" in "{1}" ({2})'.format(rest_of_key, my_key, repr(target)))
            target[rest_of_key] = value
        else:
            if isinstance(value, dict) and not isinstance(value, dotdictify):
                value = dotdictify(value)
            dict.__setitem__(self, key, value)

    def __getitem__(self, key):
        if key is None or '.' not in key:
            return dict.__getitem__(self, key)
        my_key, rest_of_key = key.split('.', 1)
        target = dict.__getitem__(self, my_key)
        if not isinstance(target, dotdictify):
            raise KeyError('cannot get "{0}" in "{1}" ({2})'.format(rest_of_key, my_key, repr(target)))
        return target[rest_of_key]

    def __contains__(self, key):
        if key is None or '.' not in key:
            return dict.__contains__(self, key)
        my_key, rest_of_key = key.split('.', 1)
        if not dict.__contains__(self, my_key):
            return False
        target = dict.__getitem__(self, my_key)
        if not isinstance(target, dotdictify):
            return False
        return rest_of_key in target

    def setdefault(self, key, default=None):
        if key not in self:
            self[key] = default
        return self[key]

    def get(self, k, d=None):
        if dotdictify.__contains__(self, k):
            return dotdictify.__getitem__(self, k)
        return d

    __setattr__ = __setitem__
    __getattr__ = __getitem__