python - 凯撒密码 - 错误输出

Question

问题是:

Your program needs to decode an encrypted text file called "encrypted.txt". The person who wrote it used a cipher specified in "key.txt". This key file would look similar to the following:

A    B
B    C
C    D
D    E
E    F
F    G
G    H
H    I
I    J
J    K
K    L
L    M
M    N
N    O
O    P
P    Q
Q    R
R    S
S    T
T    U
U    V
V    W
W    X
X    Y
Y    Z
Z    A

The left column represents the plaintext letter, and the right column represents the corresponding ciphertext.

Your program should decode the "encrypted.txt" file using "key.txt" and write the plaintext to "decrypted.txt".

我有:

decrypt = ""
keyfile = open("key.txt", "r")
cipher = {}

for keyline in keyfile:
    cipher[keyline.split()[0]] = keyline.split()[1]
keyfile.close()
encrypt = []
encryptedfile = open("encrypted.txt", "r")
readlines = encryptedfile.readlines()
str = ""

for line in readlines:
    str = line
    letter = list(str)
    for i in range(len(letter)):
        if letter[i]==",":
            decrypt += ","
        elif letter[i] == ".":
            decrypt+= "."
        elif letter[i] == "!":
            decrypt += "!"
        elif letter[i] == " ":
            decrypt += " "
        else:
            found = False
            count = 0

while (found == False):
    if (letter[i] == keyline.split()[0][count]):
        decrypt += keyline.split()[1][count]
        found = True
        count += 1
        print decrypt

encryptedfile.close()
decryptedfile = open("decrypted.txt", "w")
decryptedfile.write(decrypt)
decryptedfile.close()

这是 Python 语言。输出确实生成了一个名为 decrypted.txt 的文件，但文件中唯一的内容是 A，这对我来说没有意义。对于这个问题，它应该输出更多，对吗？

Answer 1

使用 key.txt 中给定的 key 解密文件 enrcypted.txt 并将结果保存到 decrypted.txt:

with open('key.txt', 'r') as keyfile:                                           
    pairs = [line.split() for line in keyfile]                                  
    columns = [''.join(x) for x in zip(*pairs)]                                 
    # Or to make it work with lower case letters as well:                       
    # columns = [''.join(x)+''.join(x).lower() for x in zip(*pairs)]            
    key = str.maketrans(                                                        
            *reversed(columns)                                                  
            )                                                                   

with open('encrypted.txt', 'r') as encrypted_file:                              
    decrypted = [line.translate(key) for line in encrypted_file]                

with open('decrypted.txt', 'w') as decrypted_file:
    decrypted_file.writelines(decrypted)