with open('text.txt') as f:
    credentials = [x.strip().split(':') for x in f.readlines()]

for username,password in credentials:

    user_input = input('Please Enter username: ')



    if user_input != username:

        sys.exit('Incorrect incorrect username, terminating... n')



    user_input = input('Please Enter Password: ')



    if user_input != password:

        sys.exit('Incorrect Password, terminating... n')



    print ('User is logged in!n')