networkx.algorithms.shortest_paths.unweighted.predecessor¶
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predecessor
(G, source, target=None, cutoff=None, return_seen=None)[source]¶ Returns dict of predecessors for the path from source to all nodes in G
Parameters: - G (NetworkX graph)
- source (node label) – Starting node for path
- target (node label, optional) – Ending node for path. If provided only predecessors between source and target are returned
- cutoff (integer, optional) – Depth to stop the search. Only paths of length <= cutoff are returned.
Returns: pred – Dictionary, keyed by node, of predecessors in the shortest path.
Return type: dictionary
Examples
>>> G = nx.path_graph(4) >>> list(G) [0, 1, 2, 3] >>> nx.predecessor(G, 0) {0: [], 1: [0], 2: [1], 3: [2]}