使用正则表达式标记器进行 POS 标记

如何解决使用正则表达式标记器进行 POS 标记

我想使用正则表达式标记器编写 POS 规则来修复以下标记。我的代码：

    import nltk as nltk
    from nltk import word_tokenize,UnigramTagger
    from nltk.corpus import treebank
    
    # download missing packages
    nltk.download('punkt')
    nltk.download('averaged_perceptron_tagger')
    nltk.download('treebank')

    sent1 = "My aunt's can opener can open a drum"
    tokens1 = word_tokenize(sent1)
    tag1 = nltk.pos_tag(tokens1 )
    print(tokens1)
    print(tag1)

输出

    >> output : ['My','aunt',"'s",'can','opener','open','a','drum']
    [('My','PRP$'),('aunt','NN'),("'s",'POS'),('can','MD'),('opener','VB'),('open',('a','DT'),('drum','NN')]

    patterns = [(r'\w*er\b',(r'.*',(r'(?=<\'s).*','NN')]
    default_tagger = nltk.RegexpTagger(patterns)
    train_sentences = treebank.tagged_sents()
    tagger1 = UnigramTagger(train_sentences,backoff=default_tagger)
    tagger1_2=nltk.BigramTagger(train_sentences,backoff=tagger1)
    tagger1_3=nltk.TrigramTagger(train_sentences,backoff=tagger1_2)
    tagged1_true = tagger1_3.tag(tokens1)
    tagged1_true

输出

    >> output : [('My','NN')]

我需要修复第一个“can”并使其成为“NN”