从我用来存储登录用户名和密码的文本文件顶部读取

Question

My "user.txt" contains admin username and password(admin, admin). I use it to log in. Once I register a new user into the text file, the admin username and password don't work anymore, but I can log in using the new user credentials I have just created. Please help.

importing current date
from datetime import datetime
import csv
#opening user file

user_file = open("user.txt", "r+")
text = user_file.readlines()

login = False

#while login is false,
#if user enters correct credentials, login
#changes to True. Giving excess

while login == False:

    username = input("Enter your username: ")
    password = input("Enter your password: ")

    for lines in text:
        valid_user, valid_password = lines.split(", ")
        valid_user, valid_password.strip()

    if valid_user == username and valid_password == password:
        login = True
        print("Logging in...")
    if valid_user != username and valid_password != password:
        print("Invalid login details")
    user_file.seek(0)
user_file.close()

Answer 1

At the end of the loop the valid_XXX variables just contain the last line.

You need to compare each line in the loop.

for lines in text:
    valid_user, valid_password = map(str.strip, lines.split(", "))
    
    if valid_user == username and valid_password == password:
        login = True
        print("Logging in...")
        break
    else:
        print("Invalid login details")

The else: block of a loop is executed if the loop finishes normally instead of with a break statement.