python - 属性错误 : 'FeatureChartParser' object has no attribute 'nbest_parse'

Question

我正在尝试运行此代码，以进行自然语言处理。

import  nltk
from nltk import load_parser
cp = load_parser('grammars/book_grammars/sql0.fcfg')
query = 'What cities are located in China'
trees = cp.nbest_parse(query.split())
answer = trees[0].node['sem']
q = ' '.join(answer)
print(q)

但我收到以下编译错误:

trees = cp.nbest_parse(query.split())

AttributeError: 'FeatureChartParser' 对象没有属性 'nbest_parse'

我正在使用 python3.4 和 nltk 3.0a4 。我现在可以做什么来运行它？

Answer 1

>>> import  nltk
>>> from nltk import load_parser
>>> cp = load_parser('grammars/book_grammars/sql0.fcfg')
>>> query = 'What cities are located in China'
>>> trees = next(cp.parse(query.split()))
>>> answer = trees[0].label()
>>> answer
NP[SEM=(SELECT, City FROM city_table)]