2325. Decode the Message

class Solution:
    def decodeMessage(self, key: str, message: str) -> str:
        alphabet = ['z', 'y', 'x', 'w', 'v', 'u', 't', 's', 'r', 'q', 'p', 'o', 'n', 'm', 'l', 'k', 'j', 'i', 'h', 'g', 'f', 'e', 'd', 'c', 'b', 'a']
        diction = {" ": " "}
        visited = [" "]

        for k in key:
            if k in visited:
                continue
            diction[k] = alphabet.pop()
            visited.append(k)

        return ''.join([diction[v] for v in message])