networkx.algorithms.traversal.depth_first_search.dfs_preorder_nodes¶
-
dfs_preorder_nodes
(G, source=None, depth_limit=None)[source]¶ Generate nodes in a depth-first-search pre-ordering starting at source.
- Parameters
G (NetworkX graph)
source (node, optional) – Specify starting node for depth-first search and return nodes in the component reachable from source.
depth_limit (int, optional (default=len(G))) – Specify the maximum search depth.
- Returns
nodes – A generator of nodes in a depth-first-search pre-ordering.
- Return type
generator
Examples
>>> G = nx.path_graph(5) >>> list(nx.dfs_preorder_nodes(G, source=0)) [0, 1, 2, 3, 4] >>> list(nx.dfs_preorder_nodes(G, source=0, depth_limit=2)) [0, 1, 2]
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”.
See also
dfs_edges()
,dfs_postorder_nodes()
,dfs_labeled_edges()
,bfs_edges()