python得到单词模式

def     getWordPattern(word):        pattern = []        usedLetter={}        count=0        for i in word:            if i not in usedLetter:                usedLetter[i]=count                count+=1            pattern.append(str(usedLetter[i]))        return '.'.join(pattern)def     main():        print getWordPattern("hello")if      __name__=="__main__":        main()