python - 使用JCC在pylucene/继承中编写自定义分析器？

我想在pylucene中编写一个自定义分析器。
通常在java lucene中，当您编写分析器类时，您的类会继承lucene的Analyzer类。

但是pylucene使用java到c++/python编译器jcc。

那么，如何使用jcc让python类继承自java类呢？尤其是如何编写自定义的pylucene分析器？

谢谢。

最佳答案

这是包装EdgeNGram过滤器的分析器示例。

import lucene
class EdgeNGramAnalyzer(lucene.PythonAnalyzer):
    '''
    This is an example of a custom Analyzer (in this case an edge-n-gram analyzer)
    EdgeNGram Analyzers are good for type-ahead
    '''

    def __init__(self, side, minlength, maxlength):
        '''
        Args:
            side[enum] Can be one of lucene.EdgeNGramTokenFilter.Side.FRONT or lucene.EdgeNGramTokenFilter.Side.BACK
            minlength[int]
            maxlength[int]
        '''
        lucene.PythonAnalyzer.__init__(self)
        self.side = side
        self.minlength = minlength
        self.maxlength = maxlength

    def tokenStream(self, fieldName, reader):
        result = lucene.LowerCaseTokenizer(Version.LUCENE_CURRENT, reader)
        result = lucene.StandardFilter(result)
        result = lucene.StopFilter(True, result, StopAnalyzer.ENGLISH_STOP_WORDS_SET)
        result = lucene.ASCIIFoldingFilter(result)
        result = lucene.EdgeNGramTokenFilter(result, self.side, self.minlength, self.maxlength)
        return result

这是重新实现PorterStemmer的另一个示例

# This sample illustrates how to write an Analyzer 'extension' in Python.
#
#   What is happening behind the scenes ?
#
# The PorterStemmerAnalyzer python class does not in fact extend Analyzer,
# it merely provides an implementation for Analyzer's abstract tokenStream()
# method. When an instance of PorterStemmerAnalyzer is passed to PyLucene,
# with a call to IndexWriter(store, PorterStemmerAnalyzer(), True) for
# example, the PyLucene SWIG-based glue code wraps it into an instance of
# PythonAnalyzer, a proper java extension of Analyzer which implements a
# native tokenStream() method whose job is to call the tokenStream() method
# on the python instance it wraps. The PythonAnalyzer instance is the
# Analyzer extension bridge to PorterStemmerAnalyzer.

'''
More explanation...
Analyzers split up a chunk of text into tokens...
Analyzers are applied to an index globally (unless you use perFieldAnalyzer)
Analyzers implement Tokenizers and TokenFilters.
Tokenizers break up string into tokens. TokenFilters break of Tokens into more Tokens or filter out
Tokens
'''

import sys, os
from datetime import datetime
from lucene import *
from IndexFiles import IndexFiles


class PorterStemmerAnalyzer(PythonAnalyzer):

    def tokenStream(self, fieldName, reader):

        #There can only be 1 tokenizer in each Analyzer
        result = StandardTokenizer(Version.LUCENE_CURRENT, reader)
        result = StandardFilter(result)
        result = LowerCaseFilter(result)
        result = PorterStemFilter(result)
        result = StopFilter(True, result, StopAnalyzer.ENGLISH_STOP_WORDS_SET)

        return result


if __name__ == '__main__':
    if len(sys.argv) < 2:
        sys.exit("requires at least one argument: lucene-index-path")
    initVM()
    start = datetime.now()
    try:
        IndexFiles(sys.argv[1], "index", PorterStemmerAnalyzer())
        end = datetime.now()
        print end - start
    except Exception, e:
        print "Failed: ", e

查看
perFieldAnalyzerWrapper.java
也KeywordAnalyzerTest.py

        analyzer = PerFieldAnalyzerWrapper(SimpleAnalyzer())
        analyzer.addAnalyzer("partnum", KeywordAnalyzer())

        query = QueryParser(Version.LUCENE_CURRENT, "description",
                            analyzer).parse("partnum:Q36 AND SPACE")
        scoreDocs = self.searcher.search(query, 50).scoreDocs

关于python - 使用JCC在pylucene/继承中编写自定义分析器？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/2012843/