networkx.algorithms.traversal.breadth_first_search.bfs_edges¶

bfs_edges(G, source, reverse=False)[source]¶

Iterate over edges in a breadth-first-search starting at source.

Parameters:	G (NetworkX graph) source (node) – Specify starting node for breadth-first search and return edges in the component reachable from source. reverse (bool, optional) – If True traverse a directed graph in the reverse direction
Returns:	edges – A generator of edges in the breadth-first-search.
Return type:	generator

Examples

To get the edges in a breadth-first search:

>>> G = nx.path_graph(3)
>>> list(nx.bfs_edges(G, 0))
[(0, 1), (1, 2)]

To get the nodes in a breadth-first search order:

>>> G = nx.path_graph(3)
>>> root = 2
>>> edges = nx.bfs_edges(G, root)
>>> nodes = [root] + [v for u, v in edges]
>>> nodes
[2, 1, 0]

Notes