作者：chenshuping9338 | 来源：互联网 | 2023-08-16 10:27
NLP |分块规则
原文:https://www.geeksforgeeks.org/nlp-chunking-rules/
以下是重庆的步骤——
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- 使用此树创建区块字符串。
- 通过使用正则表达式解析语法来创建正则表达式解析器。
- 将创建的组块规则应用于将句子匹配成组块的组块字符串。
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- ChunkString 然后被转换回树，有两个 chunk 子树。
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代码#1:通过应用每个规则修改 ChunkString。
Python 3
# Loading Libraries
from nltk.chunk.regexp import ChunkString, ChunkRule, ChinkRule
from nltk.tree import Tree
# ChunkString() starts with the flat tree
tree = Tree('S', [('the', 'DT'), ('book', 'NN'),
('has', 'VBZ'), ('many', 'JJ'), ('chapters', 'NNS')])
# Initializing ChunkString()
chunk_string = ChunkString(tree)
print ("Chunk String : ", chunk_string)
# Initializing ChunkRule
chunk_rule = ChunkRule('<.*>*', 'chunk determiners and nouns')
chunk_rule.apply(chunk_string)
print ("\nApplied ChunkRule : ", chunk_string)
# Another ChinkRule
ir = ChinkRule('', 'chink verbs')
ir.apply(chunk_string)
print ("\nApplied ChinkRule : ", chunk_string, "\n")
# Back to chunk sub-tree
chunk_string.to_chunkstruct()
输出:
Chunk String : <
Applied ChunkRule : { }
Applied ChinkRule : { } { }
Tree('S', [Tree('CHUNK', [('the', 'DT'), ('book', 'NN')]),
('has', 'VBZ'), Tree('CHUNK', [('many', 'JJ'), ('chapters', 'NNS')])])
注意:这段代码的工作方式与上面 ChunkRule 步骤中解释的完全相同。
代码#2:如何直接用 RegexpChunkParser 完成这个任务。
Python 3
# Loading Libraries
from nltk.chunk.regexp import ChunkString, ChunkRule, ChinkRule
from nltk.tree import Tree
from nltk.chunk import RegexpChunkParser
# ChunkString() starts with the flat tree
tree = Tree('S', [('the', 'DT'), ('book', 'NN'),
('has', 'VBZ'), ('many', 'JJ'), ('chapters', 'NNS')])
# Initializing ChunkRule
chunk_rule = ChunkRule('<.*>*', 'chunk determiners and nouns')
# Another ChinkRule
chink_rule = ChinkRule('', 'chink verbs')
# Applying RegexpChunkParser
chunker = RegexpChunkParser([chunk_rule, chink_rule])
chunker.parse(tree)
输出:
Tree('S', [Tree('CHUNK', [('the', 'DT'), ('book', 'NN')]),
('has', 'VBZ'), Tree('CHUNK', [('many', 'JJ'), ('chapters', 'NNS')])])
代码#3:用不同的 ChunkType 解析。T3】
Python 3
# Loading Libraries
from nltk.chunk.regexp import ChunkString, ChunkRule, ChinkRule
from nltk.tree import Tree
from nltk.chunk import RegexpChunkParser
# ChunkString() starts with the flat tree
tree = Tree('S', [('the', 'DT'), ('book', 'NN'),
('has', 'VBZ'), ('many', 'JJ'), ('chapters', 'NNS')])
# Initializing ChunkRule
chunk_rule = ChunkRule('<.*>*', 'chunk determiners and nouns')
# Another ChinkRule
chink_rule = ChinkRule('', 'chink verbs')
# Applying RegexpChunkParser
chunker = RegexpChunkParser([chunk_rule, chink_rule], chunk_label ='CP')
chunker.parse(tree)
输出:
Tree('S', [Tree('CP', [('the', 'DT'), ('book', 'NN')]), ('has', 'VBZ'),
Tree('CP', [('many', 'JJ'), ('chapters', 'NNS')])])
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