Inefficiency in overwriting of adjacency in undirected graphs

[eileen-kuehn]

The setting of new adjacency lists in undirected graphs is currently inefficient as first all existing edges are deleted before the new edges are inserted.

graphi/graphi/types/adjacency_graph.py

Lines 114 to 119 in a98ff1b

	# if we know node already, clean up first
	if item in self._adjacency:
	for node_to in self._adjacency[item]:
	del self._adjacency[node_to][item] # safe if graph undirected
	for node_to in value:
	self._adjacency[node_to][item] = value[node_to]