Warning
This documents an unmaintained version of NetworkX. Please upgrade to a maintained version and see the current NetworkX documentation.
dfs_predecessors¶
- dfs_predecessors(G, source=None)[source]¶
Return dictionary of predecessors in depth-first-search from source.
Parameters : G : NetworkX graph
source : node, optional
Specify starting node for depth-first search and return edges in the component reachable from source.
Returns : pred: dict
A dictionary with nodes as keys and predecessor nodes as values.
Notes
Based on http://www.ics.uci.edu/~eppstein/PADS/DFS.py by D. Eppstein, July 2004.
If a source is not specified then a source is chosen arbitrarily and repeatedly until all components in the graph are searched.
Examples
>>> G = nx.Graph() >>> G.add_path([0,1,2]) >>> print(nx.dfs_predecessors(G,0)) {1: 0, 2: 1}