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# dfs_edges

dfs_edges(G, source=None, depth_limit=None, *, sort_neighbors=None)

  Iterate over edges in a depth-first-search (DFS).

  Perform a depth-first-search over the nodes of `G` and yield the edges in order. This may not generate all edges in `G` (see `edge_dfs`).

  Parameters:
    G NetworkX graph
    source node, optional

      Specify starting node for depth-first search and yield edges in the component reachable from source.

    depth_limit int, optional (default=len(G))

      Specify the maximum search depth.

    sort_neighbors function (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.

  Yields:
    edge: 2-tuple of nodes

      Yields edges resulting from the depth-first-search.

  See also

  `dfs_preorder_nodes`
  `dfs_postorder_nodes`
  `dfs_labeled_edges`
  `edge_dfs()`
  `bfs_edges()`

  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 [1], with modifications to allow depth limits based on the Wikipedia article “Depth-limited search” [2].

  References

  [1]

  http://www.ics.uci.edu/~eppstein/PADS

  [2]

  https://en.wikipedia.org/wiki/Depth-limited_search

  Examples

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