def add_edges_from(self, ebunch, attr_dict=None, **attr):
        """Add all the edges in ebunch.

        Parameters
        ----------
        ebunch : container of edges
            Each edge given in the container will be added to the
            graph. The edges must be given as as 2-tuples (u,v) or
            3-tuples (u,v,d) where d is a dictionary containing edge
            data.
        attr_dict : dictionary, optional (default= no attributes)
            Dictionary of edge attributes.  Key/value pairs will
            update existing data associated with each edge.
        attr : keyword arguments, optional
            Edge data (or labels or objects) can be assigned using
            keyword arguments.


        See Also
        --------
        add_edge : add a single edge
        add_weighted_edges_from : convenient way to add weighted edges

        Notes
        -----
        Adding the same edge twice has no effect but any edge data
        will be updated when each duplicate edge is added.

        Examples
        --------
        >>> G = nx.Graph()   # or DiGraph, MultiGraph, MultiDiGraph, etc
        >>> G.add_edges_from([(0,1),(1,2)]) # using a list of edge tuples
        >>> e = zip(range(0,3),range(1,4))
        >>> G.add_edges_from(e) # Add the path graph 0-1-2-3

        Associate data to edges

        >>> G.add_edges_from([(1,2),(2,3)], weight=3)
        >>> G.add_edges_from([(3,4),(1,4)], label='WN2898')
        """
        # set up attribute dict
        if attr_dict is None:
            attr_dict=attr
        else:
            try:
                attr_dict.update(attr)
            except __HOLE__:
                raise NetworkXError(\
                    "The attr_dict argument must be a dictionary.")
        # process ebunch
        for e in ebunch:
            ne=len(e)
            if ne==3:
                u,v,dd = e
            elif ne==2:
                u,v = e
                dd = {}
            else:
                raise NetworkXError(\
                    "Edge tuple %s must be a 2-tuple or 3-tuple."%(e,))
            if u not in self.node:
                self.adj[u] = {}
                self.node[u] = {}
            if v not in self.node:
                self.adj[v] = {}
                self.node[v] = {}
            datadict=self.adj[u].get(v,{})
            datadict.update(attr_dict)
            datadict.update(dd)
            self.adj[u][v] = datadict
            self.adj[v][u] = datadict
dataset/ETHPy150Open gkno/gkno_launcher/src/networkx/classes/graph.py/Graph.add_edges_from