Builds the isle textfile into a dictionary for fast searching

def _buildDict(self):
        '''
        Builds the isle textfile into a dictionary for fast searching
        '''
        lexDict = {}
        with io.open(self.islePath, "r", encoding='utf-8') as fd:
            wordList = [line.rstrip('\n') for line in fd]
        
        for row in wordList:
            word, pronunciation = row.split(" ", 1)
            word, extraInfo = word.split("(", 1)
            
            extraInfo = extraInfo.replace(")", "")
            extraInfoList = [segment for segment in extraInfo.split(",")
                             if ("_" not in segment and "+" not in segment and
                                 ':' not in segment and segment != '')]
            
            lexDict.setdefault(word, [])
            lexDict[word].append((pronunciation, extraInfoList))
        
        return lexDict