新手小白求教：为什么下面代码不能将摩尔斯电码转为英.....

code=["._","_...","_._.","_..",".",".._.","__.","....","..",".___","_._","._..","__","_.","___",".__.","__._","._.","...","_",".._","..._",".__","_.._","_.__","__.."]
message=input("请输入电报：")
message+=""
chars=""
output=""
for letter in message:
    if letter!="":
        chars=chars+letter
    else:
        for index in range(26):
            if code[index]==chars:
                output+=chr(ord('A')+index)
        chars=""
print("英语原文是：",output)