skbio.tree.TreeNode.traverse#

TreeNode.traverse(self_before=True, self_after=False, include_self=True)[source]#

Traverse over tree.

Parameters:

self_beforebool, optional: Whether include each node before its descendants (default: True).
self_afterbool, optional: Whether include each node after its descendants (default: False).
include_selfbool, optional: Include the initial node if True (default).

Yields:

TreeNode: Visited node.

See also

preorder
postorder
pre_and_postorder
levelorder
tips
non_tips

Notes

This is a depth-first search (DFS). self_before and self_after determine whether a node should be visited before and after traversing its children. They are independent. If both True, each internal node (and root) will be visited twice. If neither is True, only tips will be returned.

This method is a generalization of preorder, postorder, pre_and_postorder and tips. The default mode (self_before=True, self_after=False) is equivalent to preorder traversal.

Examples

>>> from skbio import TreeNode
>>> tree = TreeNode.read(["((a,b)c,(d,e)f)g;"])
>>> print(tree.ascii_art())
                    /-a
          /c-------|
         |          \-b
-g-------|
         |          /-d
          \f-------|
                    \-e

>>> for node in tree.traverse():
...     print(node.name)
g
c
a
b
f
d
e