Python解密程序仅返回加密文本，请求协助排查故障

Hey there, let's dig into why your decryption script isn't working—there are a few key issues in the code that are keeping it from returning the decrypted text. Let's break them down one by one, then fix the code:

Key Issues in the Original Code #

• Undefined/incorrect variable handling in translate:
  Your function accepts x as a parameter but uses y internally (which isn't defined in the function scope). Worse, when you call translate(x), you're passing a file object instead of the actual text content you read from the file.

• String replace() doesn't modify in-place:
  Python strings are immutable—y.replace(old, new) returns a new string instead of changing the original y. You need to assign the result back to y for each replacement to take effect.

• Redundant while loop:
  The loop running 1000 times is unnecessary. str.replace() replaces all occurrences of the substring in one go, so a single pass through your replacement rules is enough.

• Broken file search logic:

  • The nested loops over subfolders and filenames are incorrect—os.walk already handles recursive traversal, so you don't need to loop through subfolders separately.
  • You're trying to open files using just the filename, not the full path. This will fail unless the file is in your current working directory.
  • You don't close the file after reading it—using a with statement is the safe, Pythonic way to handle files.

Corrected Code #

def translate(text):
    # Start with the input text
    decrypted = text
    # Apply all replacement rules—assign back to decrypted each time
    decrypted = decrypted.replace("quebrqerubfq92983rgh", "A")
    decrypted = decrypted.replace("837bfv8g24gh2783", "C")
    decrypted = decrypted.replace("9q37f93724f9732f", "E")
    decrypted = decrypted.replace("eqvrgb8rgbb452", "G")
    decrypted = decrypted.replace("1974f17934hf7h", "I")
    decrypted = decrypted.replace("1973f9734fbviu3", "K")
    decrypted = decrypted.replace("urhg9327hg9283g", "M")
    decrypted = decrypted.replace("18374f19374h983h", "O")
    decrypted = decrypted.replace("94fh93184hf91834f", "Q")
    decrypted = decrypted.replace("9rugueirgquierg", "S")
    decrypted = decrypted.replace("294uv94ugh293ugh928", "U")
    decrypted = decrypted.replace("29gh3i1fb94h9834h", "W")
    decrypted = decrypted.replace("193fh18934hfhb", "Y")
    decrypted = decrypted.replace("q9eurfuerhg93458htg", "B")
    decrypted = decrypted.replace("feugb2er9gh923gh", "D")
    decrypted = decrypted.replace("3ourv9u3rv93uv", "F")
    decrypted = decrypted.replace("v19u3rf9831hf89134h", "H")
    decrypted = decrypted.replace("913ufh9183hf91834", "J")
    decrypted = decrypted.replace("31uhf91384hf9834f", "L")
    decrypted = decrypted.replace("319fuh19hgf91834", "N")
    decrypted = decrypted.replace("fu3bf91u34bf1u34f", "P")
    decrypted = decrypted.replace("8134f87134fg13", "R")
    decrypted = decrypted.replace("f319u4f319u4hf3491", "T")
    decrypted = decrypted.replace("vq3yrbqbfuf", "V")
    decrypted = decrypted.replace("jirfbqiweufwqr440", "X")
    decrypted = decrypted.replace("qiuefqweurewiub", "Z")
    return decrypted

import os

target_filename = input("Enter the filename to decrypt: ")

# Walk through all directories on G: drive
for foldername, _, filenames in os.walk("g:"):
    if target_filename in filenames:
        # Build the full path to the file
        file_path = os.path.join(foldername, target_filename)
        # Use with statement to safely read the file
        with open(file_path, "r") as f:
            encrypted_text = f.read()
            decrypted_result = translate(encrypted_text)
            print("Decrypted content:\n", decrypted_result)
        # Exit after finding and processing the file (remove if you want to find multiple matches)
        break
else:
    print(f"File {target_filename} not found on G: drive.")

What Changed? #

1. Renamed function parameters for clarity: translate(text) makes it obvious what input we're working with.
2. Assigned replace() results back to a variable: Each replacement updates the decrypted string.
3. Removed the useless while loop: One pass through the rules is enough.
4. Fixed os.walk logic: We ignore subfolders (using _ as a throwaway variable) and check if the target filename exists in the current directory's files.
5. Used full file path: os.path.join ensures we open the correct file, no matter where it is on the G: drive.
6. Added with statement: Automatically closes the file after reading, preventing resource leaks.
7. Added fallback message: Tells you if the file isn't found.

内容的提问来源于stack exchange，提问作者PY_NEWBIE