Method __getitem__

recipes/Python/578615_graph/recipe-578615.py:503–514

Return value of corresponding key. If key does not exist, create it with default value. >>> g = Graph() >>> g[1].add([1,2]) >>> g[3][1] False >>> print g #NOTE: Vertex(3) created! {1: {1, 2}, 2: {}, 3: {}}

(self, vid)

            return True

    def __getitem__(self, vid): #could just set equal to GraphBaseType.setdefault, but doctest module complains
        """Return value of corresponding key.  If key does not exist, create it
        with default value.

        >>> g = Graph()
        >>> g[1].add([1,2])
        >>> g[3][1]
        False
        >>> print g  #NOTE: Vertex(3) created!
        {1: {1, 2}, 2: {}, 3: {}}
        """
        return self.setdefault(vid, {}) #will convert plain {} to VertexType if necessary

    def __setitem__(self, vid, value):
        """Set graph[vid] to VertexType(value).