Python银行程序开发：实现文件同行列的用户名密码逐行验证

我正在开发一款Python银行程序，目前遇到的问题是：无法实现逐行读取ANZData.txt文件，验证用户输入的用户名和密码是否同时存在于文件的同一行中。我曾尝试编写代码if loginuser and loginpass in file.readlines()，但运行报错，不知如何解决。现有代码如下：

accounts = {}

def login():
    
    f = open("ANZData.txt", "a")
    y = 0
    count = 0

    while y != 1:
        print("whats your username? ")
        loginuser = input()

        print("whats your password? ")
        loginpass = input()

        print("whats your PIN ")
        loginpass = input()

        # Open the file in read mode
        with open('ANZData.txt', 'r') as file:
        # Read each line in the file
            for line in file:
            #CODE NEEDED HERE
               


def register(accounts):
  
    print("what is your username?")
    user = input("enter username:")

    print("what is your Password? ")
    passw = input("enter password: ")

    print("please provide us a pin number to use")
    PIN = input("enter PIN: ")

    with open('ANZData.txt', 'a') as f:
        f.write("name: " + user + " Password: " + passw + " PIN: " + PIN + '\n') 


    with open('ANZData.txt', 'r') as file:
        for line in file:
            key, value = line.strip().split(':', 1)
            accounts[key.strip()] = value.strip()

    print(accounts)


#Main code starts here:
#--------------------------------------------------------------------------------------------#

x=1

while x != 0:

    print(accounts)
    print("Would you like to login or register?")
    logintoken = input("")

    if logintoken == "enter":
        registr = register(accounts)
    elif logintoken == "login":
        x=0
        logi = login()
    else:
        print("try again")

x=1

while x != 0:
    print(accounts)
    print("\n Do you want to withdraw, deposit or check balance?")
    decision = input("")

    if decision.upper == "Balance":
        print("placeholder")

先梳理代码里的核心问题： #

• 变量覆盖：login函数中，用户输入的密码被后续输入的PIN覆盖（都用了loginpass变量），导致密码验证根本无法进行
• 逻辑错误：if loginuser and loginpass in file.readlines()的语法逻辑不对，这个表达式实际是判断loginuser为真且loginpass在所有行的列表里，不是验证两者在同一行
• 资源泄漏：login函数开头f = open("ANZData.txt", "a")打开文件后未关闭，应该用with语句自动管理文件资源

修复后的login函数代码： #

def login():
    while True:
        print("whats your username? ")
        login_user = input().strip()

        print("whats your password? ")
        login_pass = input().strip()

        print("whats your PIN? ")
        login_pin = input().strip()

        # 逐行验证用户输入
        authenticated = False
        with open('ANZData.txt', 'r') as file:
            for line in file:
                line = line.strip()
                if not line:
                    continue  # 跳过空行
                # 按格式拆分每行内容："name: xxx Password: yyy PIN: zzz"
                parts = line.split()
                # 提取对应字段
                stored_user = parts[1]
                stored_pass = parts[3]
                stored_pin = parts[5]
                # 验证输入与存储内容是否匹配
                if stored_user == login_user and stored_pass == login_pass and stored_pin == login_pin:
                    authenticated = True
                    break
        
        if authenticated:
            print("登录成功！")
            break
        else:
            print("用户名、密码或PIN错误，请重新输入！")

额外优化建议： #

1. register函数的字典构建问题：当前用split(':', 1)拆分行会导致账户信息存储错误，可修改为：

with open('ANZData.txt', 'r') as file:
    accounts.clear()
    for line in file:
        line = line.strip()
        if not line:
            continue
        parts = line.split()
        user = parts[1]
        accounts[user] = {
            'password': parts[3],
            'pin': parts[5]
        }

2. 主逻辑的语法错误：if decision.upper == "Balance"需改为if decision.upper() == "BALANCE"，因为upper是字符串方法，必须调用才会返回大写结果

内容的提问来源于stack exchange，提问作者Atem Arok