Python如何修改txt文件中指定用户名对应的存储分数

实现思路 #

因为TXT是纯文本文件，无法直接修改某一行的内容，所以采用「全量读取-匹配修改-全量覆写」的逻辑：

• 先读取Login.txt的所有行，存入列表做临时存储
• 遍历列表中的每一行，跳过空行后拆分用户名、密码、分数三个字段
• 匹配到目标用户名后，用新分数替换原有分数，重组该行内容
• 所有行处理完成后，把修改后的列表重新写入Login.txt覆盖原有内容

完整可运行代码 #

你可以直接把下面的update_user_score函数加到你现有代码里，我同时也修复了你原有SignUp函数可能产生多余空行的问题：

def SignUp():
    print("Please enter a username and password.")
    newUsername = input("Your username: ")
    print("Cool now enter a password\n")
    newPassword = input("Your Password: ")
    print("Nice.")
    newscore = input("Now give me a score: ")
    # 判断文件是否为空，避免首行出现空行
    import os
    file_exists = os.path.exists("Login.txt")
    is_empty = not file_exists or os.path.getsize("Login.txt") == 0
    with open("Login.txt","a") as file:
        # 只有文件不是空的时候才先写换行
        if not is_empty:
            file.write("\n")
        file.write(f"{newUsername},{newPassword},{newscore}")

def Login():
    userLogin = input("Please enter your username. ")
    userPass = input("Password: ")
    logged_in = False
    current_score = 0
    with open('Login.txt', 'r') as file:
        for line in file:
            line = line.strip()
            # 跳过空行避免报错
            if not line:
                continue
            username, password, score = line.split(',')
            if username == userLogin:
                logged_in = password == userPass
                current_score = score
                break
    if logged_in:
        print(f"Login success, your current score is: {current_score}")
        # 登录成功后可选择是否更新分数
        update_choice = input("Do you want to update your score? (y/n): ").lower()
        if update_choice == 'y':
            new_score = input("Enter your new score: ")
            update_user_score(userLogin, new_score)
    else:
        print("Wrong username or password")

def update_user_score(target_username, new_score):
    # 存储所有行的临时列表
    all_lines = []
    with open("Login.txt", "r") as file:
        for line in file:
            line = line.strip()
            if not line:
                continue
            username, password, old_score = line.split(',')
            if username == target_username:
                # 匹配到目标用户，替换分数
                line = f"{username},{password},{new_score}"
            all_lines.append(line)
    # 全量覆写回文件
    with open("Login.txt", "w") as file:
        file.write('\n'.join(all_lines))
    print(f"Score updated successfully, new score is {new_score}")

# 测试运行
SignUp()
Login()

代码说明 #

• update_user_score函数接收两个参数：要修改的用户名target_username和新分数new_score
• 处理过程中会自动跳过文件中的空行，避免拆分字段时报错
• 修改完成后直接覆盖原文件，不会产生多余的临时文件
• 优化后的SignUp函数不会再产生多余的空行，避免后续读取时出现异常

内容的提问来源于stack exchange，提问作者Philip PoultonHaselier