dfs_postorder_nodes#

dfs_postorder_nodes(G, source=None, depth_limit=None, *, sort_neighbors=None)[source]#

Generate nodes in a depth-first-search post-ordering starting at source.

Parameters:
GNetworkX graph
sourcenode, optional

Specify starting node for depth-first search.

depth_limitint, optional (default=len(G))

Specify the maximum search depth.

sort_neighborsfunction (default=None)

A function that takes an iterator over nodes as the input, and returns an iterable of the same nodes with a custom ordering. For example, sorted will sort the nodes in increasing order.

Returns:
nodes: generator

A generator of nodes in a depth-first-search post-ordering.

See also

dfs_edges
dfs_preorder_nodes
dfs_labeled_edges
edge_dfs()
bfs_tree()

Notes

If a source is not specified then a source is chosen arbitrarily and repeatedly until all components in the graph are searched.

The implementation of this function is adapted from David Eppstein’s depth-first search function in PADS, with modifications to allow depth limits based on the Wikipedia article “Depth-limited search”.

Examples

>>> G = nx.path_graph(5)
>>> list(nx.dfs_postorder_nodes(G, source=0))
[4, 3, 2, 1, 0]
>>> list(nx.dfs_postorder_nodes(G, source=0, depth_limit=2))
[1, 0]
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