python版kmp

#---------------------------------------------  
#                                            -  
#author  chile                            -  
#version 1.0                               -  
#since                                       -  
#date  2014-02-17                                      -  
#desc kmp查找字符串                                       -  
#                                            -  
#                                            -  
#                                            -  
#---------------------------------------------  
  
#对子串加以预处理，找到匹配失败时子串回退的位置  
def (patter):  
    length = len(patter)  
    p = handlerList(length)  
    j = -1  
    p[0] = j   
    for i in range(1,length):  
        j = p[i - 1]  
        while j >= 0 and patter[i] != patter[j+1]:  
            j = p[j]  
          
        if patter[i] == patter[j+1]: #含有重复字符时，回退的位置+1  
            p[i] = j + 1  
        else:  
            p[i] = -1  
      
    return p  
  
#初始化一个元组  
def handlerList(len,default = 0):  
    if len <= 0:  
        return  
    p = []  
    for i in range(len):  
        p.append(default)  
    return p  
  
def kmp(value,pattern):  
    srcSize = len(value)  
    subSize = len(pattern)  
    p = preprocess(pattern)  
    tIndex , pIndex ,total = 0 , 0 , 0  
    while tIndex < srcSize and pIndex < subSize: #找到合适的回退位置  
        if (value[tIndex] == pattern[pIndex]):  
            tIndex += 1  
            pIndex += 1  
        elif pIndex == 0:  
            tIndex += 1  
        else:  
            pIndex = p[pIndex - 1] + 1  
         
        if pIndex == subSize:  #输出匹配结果，并且让比较继续下去  
            pIndex = 0  
            total += 1  
            print 'find',pattern,'at',(tIndex - subSize)  
    print 'find times ' , total  
  
      
var = 'abadfafdewefwfafd'  
pattern ='afd'  
kmp(var,pattern)