擅长:python、mysql、java
<p>您可以使用<code>treepositions('leaves')</code>(<a href="http://www.nltk.org/api/nltk.html#nltk.tree.Tree.treepositions" rel="nofollow">docs</a>)来获取树中叶子的位置,并直接在树中进行更改。在</p>
<pre><code>t = Tree(line)
chomsky_normal_form(t, horzMarkov=2, vertMarkov=1, childChar = "|", parentChar = "^")
for leafPos in t.treepositions('leaves'):
if t[leafPos] == k[0][1]:
t[leafPos] = "newValue"
print t
</code></pre>