检测 POS 标签模式以及指定的单词

Question

我需要在某些特定单词之前/之后识别某些词性标签，例如以下标记句子：

[('This', 'DT'), ('feature', 'NN'), ('would', 'MD'), ('be', 'VB'), ('nice', 'JJ'), ('to', 'TO'), ('have', 'VB')]

可以抽象为“would be”+形容词的形式

同理：

[('I', 'PRP'), ('am', 'VBP'), ('able', 'JJ'), ('to', 'TO'), ('delete', 'VB'), ('the', 'DT'), ('group', 'NN'), ('functionality', 'NN')]

是“能够”+动词的形式

我怎样才能在句子中检查这些类型的模式。我正在使用 NLTK。

Answer 1

假设您想逐字检查“would”，然后是“be”，然后是一些形容词，您可以这样做：

def would_be(tagged):
    return any(['would', 'be', 'JJ'] == [tagged[i][0], tagged[i+1][0], tagged[i+2][1]] for i in xrange(len(tagged) - 2))

输入是一个带有 POS 标记的句子（元组列表，根据 NLTK）。

它检查列表中是否存在任何三个元素，使得“would”在“be”旁边，“be”在标记为形容词（'JJ'）的单词旁边。只要匹配了这个“模式”，它就会返回True。

你可以对第二种句子做一些非常相似的事情：

def am_able_to(tagged):
    return any(['am', 'able', 'to', 'VB'] == [tagged[i][0], tagged[i+1][0], tagged[i+2][0], tagged[i+3][1]] for i in xrange(len(tagged) - 3))

这是程序的驱动程序：

s1 = [('This', 'DT'), ('feature', 'NN'), ('would', 'MD'), ('be', 'VB'), ('nice', 'JJ'), ('to', 'TO'), ('have', 'VB')]
s2 = [('I', 'PRP'), ('am', 'VBP'), ('able', 'JJ'), ('to', 'TO'), ('delete', 'VB'), ('the', 'DT'), ('group', 'NN'), ('functionality', 'NN')]

def would_be(tagged):
   return any(['would', 'be', 'JJ'] == [tagged[i][0], tagged[i+1][0], tagged[i+2][1]] for i in xrange(len(tagged) - 2))

def am_able_to(tagged):
    return any(['am', 'able', 'to', 'VB'] == [tagged[i][0], tagged[i+1][0], tagged[i+2][0], tagged[i+3][1]] for i in xrange(len(tagged) - 3))

sent1 = ' '.join(s[0] for s in s1)
sent2 = ' '.join(s[0] for s in s2)

print("Is '{1}' of type 'would be' + adj? {0}".format(would_be(s1), sent1))
print("Is '{1}' of type 'am able to' + verb? {0}".format(am_able_to(s1), sent1))

print("Is '{1}' of type 'would be' + adj? {0}".format(would_be(s2), sent2))
print("Is '{1}' of type 'am able to' + verb? {0}".format(am_able_to(s2), sent2))

这正确输出：

Is 'This feature would be nice to have' of type 'would be' + adj? True
Is 'This feature would be nice to have' of type 'am able to' + verb? False
Is 'I am able to delete the group functionality' of type 'would be' + adj? False
Is 'I am able to delete the group functionality' of type 'am able to' + verb? True

如果您想概括这一点，您可以更改是检查文字词还是它们的 POS 标签。