Question

我是一名A级计算机学生，我是班上唯一一个可以使用Python编写代码的人。甚至我的老师也没有学过这门语言。我正在尝试编写一个登录程序，当正确放入信息时退出该登录程序并显示欢迎屏幕图像（我尚未对该部分进行编码）。在3次登录尝试失败后，它必须关闭并显示失败消息。尝试更改我的尝试变量以使elif语句在多次登录失败后工作以及根据相关的if / elif语句使tkinter窗口终止/关闭时，我遇到了许多逻辑错误。这是行之有效的，我在这个网站上看了很多代码示例，找不到任何东西，我可以帮忙修一下我的代码吗？

代码：

from tkinter import * #Importing graphics

attempts = 0 #Defining attempts variable

def OperatingProgram(): #Defining active program

    class Application(Frame):
        global attempts
        def __init__(self,master):
            super(Application, self).__init__(master) #Set __init__ to the master class
            self.grid()
            self.InnerWindow() #Creates function

        def InnerWindow(self): #Defining the buttons and input boxes within the window
            global attempts
            print("Booted log in screen")
            self.title = Label(self, text=" Please log in, you have " + str(attempts) + " incorrect attempts.") #Title
            self.title.grid(row=0, column=2)

            self.user_entry_label = Label(self, text="Username: ") #Username box
            self.user_entry_label.grid(row=1, column=1)

            self.user_entry = Entry(self)                        #Username entry box
            self.user_entry.grid(row=1, column=2)

            self.pass_entry_label = Label(self, text="Password: ") #Password label
            self.pass_entry_label.grid(row=2, column=1)

            self.pass_entry = Entry(self)                        #Password entry box
            self.pass_entry.grid(row=2, column=2)

            self.sign_in_butt = Button(self, text="Log In",command = self.logging_in) #Log in button
            self.sign_in_butt.grid(row=5, column=2)

        def logging_in(self):
            global attempts
            print("processing")
            user_get = self.user_entry.get() #Retrieve Username
            pass_get = self.pass_entry.get() #Retrieve Password

            if user_get == 'octo' and pass_get == 'burger': #Statement for successful info
                import time
                time.sleep(2)       #Delays for 2 seconds
                print("Welcome!")
                QuitProgram()
            elif user_get != 'octo' or pass_get != 'burger': #Statement for any failed info
                if attempts >= 2:   #Statement if user has gained 3 failed attempts
                   import time
                   time.sleep(2)
                   print("Sorry, you have given incorrect details too many times!")
                   print("This program will now end itself")
                   QuitProgram()
                else:               #Statement if user still has enough attempts remaining
                    import time
                    time.sleep(2)
                    print("Incorrect username, please try again")
                    attempts += 1
            else:                   #Statement only exists to complete this if statement block
                print("I don't know what you did but it is very wrong.")

    root = Tk() #Window format
    root.title("Log in screen")
    root.geometry("320x100")

    app = Application(root) #The frame is inside the widget
    root.mainloop() #Keeps the window open/running

def QuitProgram(): #Defining program termination
    import sys
    sys.exit()

OperatingProgram()

Answer 1

请考虑logging_in方法中的以下两行：

if user_get == 'octo' and pass_get == 'burger':
elif user_get != 'octo' or pass_get != 'burger':

因此，如果登录凭据正确，则执行第一次测试后的代码。如果它们不正确，则执行第二次测试后的代码。

但是，您希望在多次失败后执行的代码属于第三个测试子句：

elif attempts >= 3:

问题是，执行的线程永远不会看到这个测试，因为第一个或第二个已经评估为true（登录凭据是正确的，登录凭据是不正确的） - 它们可能需要它们两者都要在检查尝试值之前评估为假。

解决此问题的最简单方法是更改

elif attempts >= 3:

行阅读

if attempts >= 3:

如果您觉得有必要，可以调整else子句/添加一个新子句。

如何在没有按钮的情况下关闭tkinter窗口？

1 个答案: