在python中使用stanford分析器時不打印結果NLTK

Question

我使用以下代碼在python NLTK中打印分析樹的結果。

 import os 
     import nltk 
     from nltk.parse import stanford 
     from nltk.tokenize import sent_tokenize 
     os.environ['STANFORD_PARSER'] = '/home/gadheyan/Project/stanford-parser-full-2014-08-27' 
     os.environ['STANFORD_MODELS'] = '/home/gadheyan/Project/stanford-parser-full-2014-08-27' 
     parser = stanford.StanfordParser(model_path="/home/gadheyan/Project/stanford-parser-full-2014-08-27/stanford-parser-3.4.1-models/edu/stanford/nlp/models/lexparser/englishPCFG.ser.gz") 
     sentences = parser.raw_parse_sents(["A rare black squirrel has become a regular visitor to a suburban garden"]) 
     print sentences 

我期待的結果如下：

(ROOT 
    (S 
    (NP (DT A) (JJ rare) (JJ black) (NN squirrel)) 
    (VP 
     (VBZ has) 
     (VP 
     (VBN become) 
     (NP (DT a) (JJ regular) (NN visitor)) 
     (PP (TO to) (NP (DT a) (JJ suburban) (NN garden))))))) 

，但我得到的結果作爲

<listiterator object at 0x7f6ed5c30890> 

爲什麼會發生呢？

Answer 1

raw_parse_sents的返回類型是iter（iter（Tree）），而不是字符串。 http://www.nltk.org/_modules/nltk/parse/stanford.html

嘗試：

for line in sentences: 
    for sentence in line: 
     sentence.draw() 

Stanford Parser and NLTK