字母表新旧对照替换加密

from string import ascii_lowercase as strs
while True:
    try:
        key=input()
        wd=input()
        newstrs=""
        temp=key+strs
        # print(len(temp), temp)#测试,看长度
        for i in temp:
            if i not in newstrs:
                newstrs+=i
        # newstrs=list(set(temp))#不能用这种方法去重,集合去重是无序的
        # print(len(newstrs),newstrs)#测试,看长度
        res='' #保存结果
        for i in wd:
            if i.isupper():
                res+=newstrs[strs.find(i)].upper()
            else:
                res+=newstrs[strs.find(i)]
        print(res)
    except:
        break