networkx.algorithms.predecessor¶

networkx.algorithms.predecessor(G, source, target=None, cutoff=None, return_seen=None)[source]¶

Returns dictionary 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 Dictionary, keyed by node, of predecessors in the shortest path.

Examples

>>> G = nx.path_graph(4)
>>> list(G)
[0, 1, 2, 3]
>>> nx.predecessor(G, 0)
{0: [], 1: [0], 2: [1], 3: [2]}