修复密码存储程序view函数抛出的ValueError问题

我跟着教程写了一个带添加、查看、存储密码功能的程序，但每次运行view函数都会抛出ValueError。具体代码和报错信息如下：

代码 #

from cryptography.fernet import Fernet

'''
def write_key():
    key = Fernet.generate_key()
    with open("key.key", "wb") as key_file:
        key_file.write(key)
'''

def load_key():
    file = open("key.key", "rb")
    key = file.read()
    file.close()
    return key

key = load_key()
fer = Fernet(key)

def view():
    with open('passwords.txt', 'r') as f:
        for line in f.readlines():
            data = line.rstrip()
            user, passw = data.split("|")
            print("User:", user, "| Password:",fer.decrypt(passw.encode()).decode())
def add():
    name = input('Account Name: ')
    pwd = input("Password: ")

    with open('passwords.txt', 'a') as f:
        f.write(name + "|" + fer.encrypt(pwd.encode()).decode() + "\n")

while True:
    mode = input("Would you like to add a new password or view existing ones (view, add), press q to quit? ").lower()
    if mode == "q":
        break
    if mode == "view":
        view()
    elif mode == "add":
        add()
    else:
        print("Invalid mode.")
        continue

报错输出 #

Would you like to add a new password or view existing ones (view, add), press q to quit? view
    ---------------------------------------------------------------------------
    ValueError                                Traceback (most recent call last)
    <ipython-input-18-234bb8d48400> in <module>
         35         break
         36     if mode == "view":
    ---> 37         view()
         38     elif mode == "add":
         39         add()
    
    <ipython-input-18-234bb8d48400> in view()
         21         for line in f.readlines():
         22             data = line.rstrip()
    ---> 23             user, passw = data.split("|")
         24             print("User:", user, "| Password:",fer.decrypt(passw.encode()).decode())
         25 def add():

ValueError: too many values to unpack (expected 2)

解决方案 #

这个错误的核心是passwords.txt里的某一行用|分割后，得到的元素数量不是2，没法赋值给user, passw两个变量。以下是具体解决办法：

1. 检查并修复密码文件内容 #

打开passwords.txt，逐行排查：

• 是否有包含多个|的行（比如账户名里误输入了|）
• 是否有空行或者没有|的无效行
• 是否存在之前手动写入的不符合用户名|加密密码格式的内容

把这些异常行删除或修正成正确格式即可。

2. 限制split的分割次数 #

修改view函数里的split语句，添加maxsplit=1参数，确保只以第一个|为分隔符，就算账户名里包含|也不会出错：

user, passw = data.split("|", 1)

3. 添加异常处理避免崩溃 #

给view函数加上异常捕获，遇到格式错误的行时跳过并提示，防止程序直接崩溃：

def view():
    with open('passwords.txt', 'r') as f:
        for line in f.readlines():
            data = line.rstrip()
            try:
                user, passw = data.split("|", 1)
                print("User:", user, "| Password:", fer.decrypt(passw.encode()).decode())
            except ValueError:
                print(f"跳过格式错误的行: {data}")

内容的提问来源于stack exchange，提问作者Axel Palomino