networkx.Graph.add_edge¶
-
Graph.
add_edge
(u_of_edge, v_of_edge, **attr)[source]¶ Add an edge between u and v.
The nodes u and v will be automatically added if they are not already in the graph.
Edge attributes can be specified with keywords or by directly accessing the edge’s attribute dictionary. See examples below.
- Parameters
u, v (nodes) – Nodes can be, for example, strings or numbers. Nodes must be hashable (and not None) Python objects.
attr (keyword arguments, optional) – Edge data (or labels or objects) can be assigned using keyword arguments.
See also
add_edges_from()
add a collection of edges
Notes
Adding an edge that already exists updates the edge data.
Many NetworkX algorithms designed for weighted graphs use an edge attribute (by default
weight
) to hold a numerical value.Examples
The following all add the edge e=(1, 2) to graph G:
>>> G = nx.Graph() # or DiGraph, MultiGraph, MultiDiGraph, etc >>> e = (1, 2) >>> G.add_edge(1, 2) # explicit two-node form >>> G.add_edge(*e) # single edge as tuple of two nodes >>> G.add_edges_from([(1, 2)]) # add edges from iterable container
Associate data to edges using keywords:
>>> G.add_edge(1, 2, weight=3) >>> G.add_edge(1, 3, weight=7, capacity=15, length=342.7)
For non-string attribute keys, use subscript notation.
>>> G.add_edge(1, 2) >>> G[1][2].update({0: 5}) >>> G.edges[1, 2].update({0: 5})