Question

我尝试过nltk.org第7章。特别是在这里：http://www.nltk.org/book/ch07.html在3.2节下面有一个ConsecutiveNPChunker类。我试图复制代码。但是，它始终抛出以下ValueError。

我的代码如下：

import nltk
from nltk.corpus import conll2000
train_sents = conll2000.chunked_sents('train.txt', chunk_types=['NP'])
class ConsecutiveNPChunker(nltk.ChunkParserI): # [_consec-chunker]
    def __init__(self, train_sents):
        tagged_sents = [[((w,t),c) for (w,t,c) in
                         nltk.chunk.tree2conlltags(sent)]
                        for sent in train_sents]
        self.tagger = ConsecutiveNPChunkTagger(tagged_sents)

    def parse(self, sentence):
        tagged_sents = self.tagger.tag(sentence)
        conlltags = [(w,t,c) for ((w,t),c) in tagged_sents]
        return nltk.chunk.conlltags2tree(conlltags)
def npchunk_features(sentence, i, history):
    word, pos = sentence[i]
    return {"pos": pos}
chunker = ConsecutiveNPChunker(train_sents)

以下是我运行程序时的错误：

~/.pyenv/versions/3.4.3/envs/nlp/lib/python3.4/site-packages/nltk/tag/util.py in <listcomp>(.0)
     67 
     68     """
---> 69     return [w for (w, t) in tagged_sentence]
     70 
     71 

ValueError: need more than 1 value to unpack

Answer 1

你有一个解包错误，这是因为你没有zip方法，它需要n个迭代次数并返回元组列表。所以，在def parse()方法/函数的代码中，

conlltags = [(w,t,c) for ((w,t),c) in tagged_sents]

这应该是

conlltags = [(w,t,c) for ((w,t),c) in zip(tagged_sents)]

这将产生多个解包值。

NLTK ConsecutiveNPChunker抛出了ValueError

1 个答案: