nltk.ImmutableTree.treepositions¶

ImmutableTree.treepositions(order=u'preorder')¶

>>> t = Tree.fromstring("(S (NP (D the) (N dog)) (VP (V chased) (NP (D the) (N cat))))")
>>> t.treepositions() 
[(), (0,), (0, 0), (0, 0, 0), (0, 1), (0, 1, 0), (1,), (1, 0), (1, 0, 0), ...]
>>> for pos in t.treepositions('leaves'):
...     t[pos] = t[pos][::-1].upper()
>>> print(t)
(S (NP (D EHT) (N GOD)) (VP (V DESAHC) (NP (D EHT) (N TAC))))

Parameters:	order – One of: preorder, postorder, bothorder, leaves.