self.bell()创建一个RecursionError

Question

我正在开发一个密码管理器，分为几个类。当某个条件不满足时，我想要一个铃声来通知用户。在代码的一个更简单的版本中，我使用了很好的旧的self.bell()，没有问题(所有的代码都在一个类下--不好，所以升级了版本)。在升级后的代码中，我得到了一个递归错误。

我已经经历了我能想到的一切，没有任何乐趣。在各种论坛上，我似乎找不到任何与我的案例足够接近的案例。我在windows7上使用pycharm 2019.1.3。

主文件：

from class_createNewPassword import *
from class_searchDatabase import *
from class_updateDatabase import *


class display(Tk):
    def __init__(self, master=None):
        # main window
        Tk.__init__(self, master)
        self.title('Password Manager')

        buttonCreate = ttk.Button(self, text='Create a new password', command=createNewPassword)
        buttonCreate.grid(column=0, row=0)

        buttonSearch = ttk.Button(self, text='Search the database', command=SearchDatabase)
        buttonSearch.grid(column=1, row=2)

        buttonUpdate = ttk.Button(self, text='Update the database', command=UpdateDatabase)
        buttonUpdate.grid(column=2, row=4)


if __name__ == "__main__":
app = display()
app.mainloop()

问题所在的文件：

from tkinter import *
from tkinter import ttk
import tkinter as tk
from class_makePassword import *


class createNewPassword(Tk):
    def __init__(self):
        createWindow = tk.Toplevel()
        createWindow.title('Create a password')

        Toplevel.connection = sqlite3.connect("mdp - Copy.db")
        Toplevel.cursor = Toplevel.connection.cursor()
        self.connection = Toplevel.connection
        self.cursor = Toplevel.cursor

        #bunch of tkinter variables and stuff, and some functions not related to the issue


    def savePassword(self, condition):

        if condition:  #writes data in the DB, works well
            pass
        else:
            print("problem")
            self.bell()  #problem is here

我收到这个错误消息：

Exception in Tkinter callback
Traceback (most recent call last):
File "F:\Python37-32\lib\tkinter\__init__.py", line 1705, in __call__
return self.func(*args)
File "I:\01 Programs\01 On the way\SQL\password manager with classes\class_createNewPassword.py", line 249, in savePassword
self.bell()
File "F:\Python37-32\lib\tkinter\__init__.py", line 783, in bell
self.tk.call(('bell',) + self._displayof(displayof))
File "F:\Python37-32\lib\tkinter\__init__.py", line 2101, in __getattr__
return getattr(self.tk, attr)
File "F:\Python37-32\lib\tkinter\__init__.py", line 2101, in __getattr__
return getattr(self.tk, attr)
File "F:\Python37-32\lib\tkinter\__init__.py", line 2101, in __getattr__
return getattr(self.tk, attr)
[Previous line repeated 493 more times]
RecursionError: maximum recursion depth exceeded while calling a Python object

有人能告诉我我的代码出了什么问题吗？谢谢。

Answer 1

问题的根源在于您的createNewPassword类继承了Tk，但是您没有调用Tk.__init__来正确地初始化该类。

我完全看不出你为什么要继承Tk。相反，从Toplevel继承并正确初始化它：

class createNewPassword(Toplevel):
    def __init__(self):
        Toplevel.__init__(self)
        self.title('Create a password')
        ...

    def savePassword(self, condition):

        if condition:
            pass
        else:
            self.bell()