networkx.classes.function.set_edge_attributes¶
-
set_edge_attributes
(G, values, name=None)[source]¶ Sets edge attributes from a given value or dictionary of values.
Warning
The call order of arguments
values
andname
switched between v1.x & v2.x.- Parameters
G (NetworkX Graph)
values (scalar value, dict-like) – What the edge attribute should be set to. If
values
is not a dictionary, then it is treated as a single attribute value that is then applied to every edge inG
. This means that if you provide a mutable object, like a list, updates to that object will be reflected in the edge attribute for each edge. The attribute name will bename
.If
values
is a dict or a dict of dict, it should be keyed by edge tuple to either an attribute value or a dict of attribute key/value pairs used to update the edge’s attributes. For multigraphs, the edge tuples must be of the form(u, v, key)
, whereu
andv
are nodes andkey
is the edge key. For non-multigraphs, the keys must be tuples of the form(u, v)
.name (string (optional, default=None)) – Name of the edge attribute to set if values is a scalar.
Examples
After computing some property of the edges of a graph, you may want to assign a edge attribute to store the value of that property for each edge:
>>> G = nx.path_graph(3) >>> bb = nx.edge_betweenness_centrality(G, normalized=False) >>> nx.set_edge_attributes(G, bb, "betweenness") >>> G.edges[1, 2]["betweenness"] 2.0
If you provide a list as the second argument, updates to the list will be reflected in the edge attribute for each edge:
>>> labels = [] >>> nx.set_edge_attributes(G, labels, "labels") >>> labels.append("foo") >>> G.edges[0, 1]["labels"] ['foo'] >>> G.edges[1, 2]["labels"] ['foo']
If you provide a dictionary of dictionaries as the second argument, the entire dictionary will be used to update edge attributes:
>>> G = nx.path_graph(3) >>> attrs = {(0, 1): {"attr1": 20, "attr2": "nothing"}, (1, 2): {"attr2": 3}} >>> nx.set_edge_attributes(G, attrs) >>> G[0][1]["attr1"] 20 >>> G[0][1]["attr2"] 'nothing' >>> G[1][2]["attr2"] 3