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。