Class UserDict

Lib/collections/__init__.py:1172–1261

################################################################################

class UserDict(_collections_abc.MutableMapping):

    # Start by filling-out the abstract methods
    def __init__(self, dict=None, /, **kwargs):
        self.data = {}
        if dict is not None:
            self.update(dict)
        if kwargs:
            self.update(kwargs)

    def __len__(self):
        return len(self.data)

    def __getitem__(self, key):
        if key in self.data:
            return self.data[key]
        if hasattr(self.__class__, "__missing__"):
            return self.__class__.__missing__(self, key)
        raise KeyError(key)

    def __setitem__(self, key, item):
        self.data[key] = item

    def __delitem__(self, key):
        del self.data[key]

    def __iter__(self):
        return iter(self.data)

    # Modify __contains__ and get() to work like dict
    # does when __missing__ is present.
    def __contains__(self, key):
        return key in self.data

    def get(self, key, default=None):
        if key in self:
            return self[key]
        return default


    # Now, add the methods in dicts but not in MutableMapping
    def __repr__(self):
        return repr(self.data)

    def __or__(self, other):
        if isinstance(other, UserDict):
            return self.__class__(self.data | other.data)
        if isinstance(other, (dict, frozendict)):
            return self.__class__(self.data | other)
        return NotImplemented

    def __ror__(self, other):
        if isinstance(other, UserDict):
            return self.__class__(other.data | self.data)
        if isinstance(other, (dict, frozendict)):
            return self.__class__(other | self.data)
        return NotImplemented