使用exit()，我得到 "ValueError: 对已关闭的文件进行IO操作。"

Question

我正在学习Python，当我试图建立一个身份验证器（登录）时，我遇到了这个错误。

credentials = {
    "Peter" : "123",
    "Chris" : "Ga1",
    "Michael" : "uwu",
    "Steve" : "xdx10"
}
entered_username = None
entered_password = None
username_errors = 0
password_errors = 0

while True:
    entered_username = input("Please enter your username: ")
    entered_password = input("Please enter your password: ")
    try:
        if entered_password != credentials[entered_username]:
            password_errors += 1
            if password_errors == 5:
                print("Your account has been locked for security reasons.")
                exit()
            print("Wrong username or password, try again.")
            continue
        else:
            print("success 1")
    except:
        username_errors += 1
        if password_errors + username_errors == 5:
            print("Please try again at a later time.")
        print("Wrong username or password, try again.")
        continue
    print("Welcome {}! Your password is {}.".format(entered_username, entered_password))
    break

所以 exit() 中，在代码的一半左右，在 if 块状 if 块的 try 块。

运行代码，五次输入正确的密码失败，应该是让它打印 "你的账户因安全原因已被锁定。"然后退出代码。但是，它却做出了这样的回溯。

如果我把 exit()，回溯消失了。

我不知道是不是因为这个 tryexcept, 但我一直试图解决这个问题，像一个吓人的小时，我死在里面 (ಠ_ಠ).

EDIT : 没有粘贴追溯 (facepalm)

Your account has been locked for security reasons.
Wrong username or password, try again.
Please enter your username: Traceback (most recent call last):
  File "C:/Users/myname/PycharmProjects/stem1401python/py200603/login_form_v3/stem1401_python_login_form_v3.py", line 42, in <module>
    entered_username = input("Please enter your username: ")
ValueError: I/O operation on closed file.

我再补充一下这个。我不知道为什么在exit()之后还能打印出一些东西来. 比如就在 print("Your account has been locked for security reasons.") 有 exit()

Answer 1

Your account has been locked for security reasons.
Wrong username or password, try again.
Please enter your username: Traceback (most recent call last):
  File "C:/Users/myname/PycharmProjects/stem1401python/py200603/login_form_v3/stem1401_python_login_form_v3.py", line 42, in <module>
    entered_username = input("Please enter your username: ")
ValueError: I/O operation on closed file.

上述错误是由于 pycharm ide 到了 exit() 文件中的一行，它只是 closes the file not terminates the running process 所以当它到达continue的时候，它又回到了循环，当它试图获取输入()的时候，它 throws a traceback that the IO ops can't be done in closed files所以这就是问题所在，如果你用闲置运行文件，它将成功运行，没有回溯，因为。it will automatically kill the running process when file is exited ，或者如果你想在pycharm中运行代码，只需使用 os.abort() 而不是 exit() 因为它将中止进程

credentials = {
    "Peter" : "123",
    "Chris" : "Ga1",
    "Michael" : "uwu",
    "Steve" : "xdx10"
}
entered_username = None
entered_password = None
username_errors = 0
password_errors = 0
import os
while True:
    entered_username = input("Please enter your username: ")
    entered_password = input("Please enter your password: ")
    try:
        if entered_password != credentials[entered_username]:
            password_errors += 1
            if password_errors == 5:
                print("Your account has been locked for security reasons.")
                os.abort()
            print("Wrong username or password, try again.")
            continue
        else:
            print("success 1")
    except:
        username_errors += 1
        if password_errors + username_errors == 5:
            print("Please try again at a later time.")
        print("Wrong username or password, try again.")
        continue
    print("Welcome {}! Your password is {}.".format(entered_username, entered_password))
    break