python程序登录不工作

Question

list_names = ("A"+"B"+"C")
username = input("enter your username: ")
if username == (list_names):
    password = input("enter your password "+username+": ")
elif username !=(list_names):
    print("that is not a valid username")
if password == ("password"):
    print("allowing access...")
    time.sleep(3)
elif password != ("Password"):
    print("password was incorrect "+username)

我试图为我正在做的一个项目制定一个计划，但我遇到了一个问题。我已经尝试了很长一段时间，为什么这不起作用，但我无法理解为什么它打印这个错误：

Traceback (most recent call last):
  File "C:\Users\Owner\Documents\PYTHON\My Work.py", line 10, in <module>
    if password == ("password"):
NameError: name 'password' is not defined

Answer 1

您在if块内定义password，因此如果if块不执行，password将保持未定义状态。此外，您的list_names语法不正确。更新

list_names = ("A"+"B"+"C")

至

list_names = ['A','B','C']

前者执行

list_names = ("ABC")