python实现中文分词FMM算法实例_Python

本文实例讲述了python实现中文分词FMM算法。分享给大家供大家参考。具体分析如下：

FMM算法的最简单思想是使用贪心算法向前找n个，如果这n个组成的词在词典中出现，就ok，如果没有出现，那么找n-1个...然后继续下去。假如n个词在词典中出现，那么从n+1位置继续找下去，直到句子结束。

									import re  

									def PreProcess(sentence,edcode="utf-8"):  

									  sentence = sentence.decode(edcode)  

									  sentence=re.sub(u"[。，,！……!《》<>\"':：？\?、\|“”‘'；]"," ",sentence)  

									  return sentence  

									def FMM(sentence,diction,result = [],maxwordLength = 4,edcode="utf-8"):

									  i = 0

									  sentence = PreProcess(sentence,edcode)  

									  length = len(sentence)  

									  while i < length: 

									    # find the ascii word  

									    tempi=i  

									    tok=sentence[i:i+1]  

									    while re.search("[0-9A-Za-z\-\+#@_\.]{1}",tok)<>None:  

									      i= i+1

									      tok=sentence[i:i+1]  

									    if i-tempi>0:  

									      result.append(sentence[tempi:i].lower().encode(edcode)) 

									    # find chinese word  

									    left = len(sentence[i:])  

									    if left == 1:  

									      """go to 4 step over the FMM"""

									      """should we add the last one? Yes, if not blank"""

									      if sentence[i:] <> " ":  

									        result.append(sentence[i:].encode(edcode))  

									      return result  

									    m = min(left,maxwordLength)  

									    for j in xrange(m,0,-1):  

									      leftword = sentence[i:j+i].encode(edcode) 

									     #  print leftword.decode(edcode)  

									      if LookUp(leftword,diction): 

									        # find the left word in dictionary 

									        # it's the right one  

									        i = j+i  

									        result.append(leftword)  

									        break

									      elif j == 1:  

									        """only one word, add into result, if not blank"""

									        if leftword.decode(edcode) <> " ":  

									          result.append(leftword)  

									        i = i+1

									      else:  

									        continue

									  return result  

									def LookUp(word,dictionary):  

									  if dictionary.has_key(word):  

									    return True

									  return False

									def ConvertGBKtoUTF(sentence):  

									  return sentence.decode('gbk').encode('utf-8')

									dictions = {}  

									dictions["ab"] = 1

									dictions["cd"] = 2

									dictions["abc"] = 1

									dictions["ss"] = 1

									dictions[ConvertGBKtoUTF("好的")] = 1

									dictions[ConvertGBKtoUTF("真的")] = 1

									sentence = "asdfa好的是这样吗vasdiw呀真的daf dasfiw asid是吗？"

									s = FMM(ConvertGBKtoUTF(sentence),dictions)  

									for i in s:  

									  print i.decode("utf-8")

									test = open("test.txt","r")  

									for line in test:  

									  s = FMM(CovertGBKtoUTF(line),dictions)  

									  for i in s:  

									    print i.decode("utf-8")

运行结果如下：

asdfa
好的
是
这
样
吗
vasdiw
呀
真的
daf
dasfiw
asid
是
吗
？

希望本文所述对大家的Python程序设计有所帮助。

python实现中文分词FMM算法实例

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