python|python正向最大匹配分词和逆向最大匹配分词

正向最大匹配
【python|python正向最大匹配分词和逆向最大匹配分词】

# -*- coding:utf-8 -*-CODEC='utf-8'def u(s, encoding): 'converted other encoding to unicode encoding' if isinstance(s, unicode): return s else: return unicode(s, encoding)def fwd_mm_seg(wordDict, maxLen, str): 'forward max match segment' wordList = [] segStr = str segStrLen = len(segStr) for word in wordDict: print 'word: ', word print "\n" while segStrLen > 0: if segStrLen > maxLen: wordLen = maxLen else: wordLen = segStrLen subStr = segStr[0:wordLen] print "subStr: ", subStr while wordLen > 1: if subStr in wordDict: print "subStr1: %r" % subStr break else: print "subStr2: %r" % subStr wordLen = wordLen - 1 subStr = subStr[0:wordLen] #print "subStr3: ", subStr wordList.append(subStr) segStr = segStr[wordLen:] segStrLen = segStrLen - wordLen for wordstr in wordList: print "wordstr: ", wordstr return wordListdef main(): fp_dict = open('words.dic') wordDict = {} for eachWord in fp_dict: wordDict[u(eachWord.strip(), 'utf-8')] = 1 segStr = u'你好世界hello world' print segStr wordList = fwd_mm_seg(wordDict, 10, segStr) print "==".join(wordList)if __name__ == '__main__': main()

逆向最大匹配
# -*- coding:utf-8 -*-def u(s, encoding): 'converted other encoding to unicode encoding' if isinstance(s, unicode): return s else: return unicode(s, encoding)CODEC='utf-8'def bwd_mm_seg(wordDict, maxLen, str): 'forward max match segment' wordList = [] segStr = str segStrLen = len(segStr) for word in wordDict: print 'word: ', word print "\n" while segStrLen > 0: if segStrLen > maxLen: wordLen = maxLen else: wordLen = segStrLen subStr = segStr[-wordLen:None] print "subStr: ", subStr while wordLen > 1: if subStr in wordDict: print "subStr1: %r" % subStr break else: print "subStr2: %r" % subStr wordLen = wordLen - 1 subStr = subStr[-wordLen:None] #print "subStr3: ", subStr wordList.append(subStr) segStr = segStr[0: -wordLen] segStrLen = segStrLen - wordLen wordList.reverse() for wordstr in wordList: print "wordstr: ", wordstr return wordListdef main(): fp_dict = open('words.dic') wordDict = {} for eachWord in fp_dict: wordDict[u(eachWord.strip(), 'utf-8')] = 1 segStr = ur'你好世界hello world' print segStr wordList = bwd_mm_seg(wordDict, 10, segStr) print "==".join(wordList)if __name__ == '__main__': main()



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