Python Caesar Cipher 项目，输出不正确

Question

我似乎无法让这个我应该为项目做的程序输出正确的输出，即使我已经尝试让它工作多次。项目是：

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". Your program should handle both upper and lower case letters in the encrypted without having two key files (or duplicating keys). You may have the decrypted text in all caps. You should be able to handle characters in the encrypted text that are not in your key file. In that case, just have the decryption repeat the character. This will allow you to have spaces in your encrypted text that remain spaces when decrypted. While you may write a program to create the key file - do NOT include that in the submission. You may manually create the encrypted and key text files. Use either the "new file" option in Python Shell (don't forget to save as txt) or an editor such as notepad. Do not use word.

这是我的代码：

keyFile = open("key.txt", "r")
keylist1= []
keylist2 = []

for line in keyFile:
  keylist1.append(line.split()[0])
  keylist2.append(line.split()[1])
keyFile.close()
encryptedfile = open("encrypted.txt", "r")
lines = encryptedfile.readlines()
currentline = ""
decrypt = ""
for line in lines: 
  currentline = line
  letter = list(currentline)
  for i in range(len(letter)):
    currentletter = letter[i]
    if not letter[i].isalpha():
      decrypt += letter[i]
    else:
      for o in range(len(keylist1)):
        if currentletter == keylist1[o]:
          decrypt += keylist2[o]
print(decrypt)

我得到的唯一输出是：

, ?

这是不正确的。

Answer 1

您忘记处理小写字母了。使用 upper() 将所有内容转换为常见情况。

用字典代替一对列表会更好。

mapping = {}
with open("key.txt", "r") as keyFile:
    for line in keyFile:
        l1, l2 = line.split()
        mapping[upper(l1)] = upper(l2)
decrypt = ""
with open("encrypted.txt", "r") as encryptedFile:
    for line in encryptedFile:
        for char in line:
            char = upper(char)
            if char in mapping:
                decrypt += mapping[char]
            else:
                decrypt += char
print(decrypt)

Python Caesar Cipher 项目，输出不正确

Python Caesar Cipher project, incorrect output

python

encryption

cryptography

caesar-cipher