【问题和解决】NLTK7.6节nltk.sem遇到的问题

Traceback (most recent call last):
File "<pyshell#155>", line 3, in <module>
print nltk.sem.show_raw_rtuple(rel,Icon=True,rcon=True)
AttributeError: 'module' object has no attribute 'show_raw_rtuple'

在7.6关系抽取中，有这样一段代码

>>>IN = re.compile(r'.*\bin\b(?!\b.+ing)')
>>>for docin nltk.corpus.ieer.parsed_docs('NYT_19980315'):
... for rel in nltk.sem.extract_rels('ORG', 'LOC', doc,
... corpus='ieer',pattern = IN):
... print nltk.sem.show_raw_rtuple(rel)
[ORG: 'WHYY'] 'in' [LOC: 'Philadelphia']
[ORG: 'McGlashan &Sarrail']'firm in' [LOC: 'San Mateo']
[ORG: 'Freedom Forum']'in' [LOC: 'Arlington']
[ORG: 'Brookings Institution'] ', the research group in' [LOC: 'Washington']
[ORG: 'Idealab'] ', a self-described businessincubator basedin' [LOC: 'Los Angeles']
[ORG: 'Open Text']', basedin' [LOC: 'Waterloo']
[ORG: 'WGBH'] 'in' [LOC: 'Boston']
[ORG: 'Bastille Opera']'in' [LOC: 'Paris']
255
[ORG: 'Omnicom'] 'in' [LOC: 'New York']
[ORG: 'DDB Needham']'in' [LOC: 'New York']
[ORG: 'Kaplan ThalerGroup']'in' [LOC: 'New York']
[ORG: 'BBDO South']'in' [LOC: 'Atlanta']
[ORG: 'Georgia-Pacific'] 'in' [LOC: 'Atlanta']

其中有一句是

nltk.sem.show_raw_rtuple(rel)，但是运行出现了错误，提示没有此方法。
经过查询NLTK.sem的文档，发现这些函数都在更深的地方。也就是
nltk.sem.relextract中。
详情请参考：
http://nltk.googlecode.com/svn/trunk/doc/api/nltk.sem.relextract-module.html