Tkinter TopLevel窗口删除循环创建按钮后重进出现重复按钮bug求解

我创建了一个主窗口，可从主窗口进入TopLevel子窗口，子窗口会根据数据库数据循环创建按钮，默认示例会生成名称为Test1、Test2、Test3、Test4、Test5的5个按钮。
点击任意按钮后会显示类似0/4的计数器，点击「Pay selected」按钮后计数器会变为1/4，以此类推。当计数器达到对应总期数时，该按钮会被删除，此阶段运行正常。但如果我退出TopLevel窗口再从主窗口重新进入，被删除按钮旁边的按钮会占据已删除按钮的位置，同时还保留自身原有位置，最终按钮数量看起来和删除前一致，但出现重复名称的按钮。
我单独写了简化版代码可以正常运行没有这个bug，但主代码的bug一直找不到，下面附上两份代码。

主代码 #

from tkinter import *
import sqlite3

conn = sqlite3.connect('Financije.db')
c = conn.cursor()

c.execute('''CREATE TABLE IF NOT EXISTS PRIMANJA
             ([ID] INTEGER PRIMARY KEY,[Opis] text, [Iznos] integer, [Datum] text)''')

c.execute('''CREATE TABLE IF NOT EXISTS OTPLATA_NA_RATE
             ([ID] INTEGER PRIMARY KEY,[Opis] text, [Iznos_rate] integer, [Broj_rata] text, [Datum_kupnje] text)''')

c.execute('''CREATE TABLE IF NOT EXISTS SKIDANJE_S_RAČUNA
             ([ID] INTEGER PRIMARY KEY,[Opis] text, [Iznos] integer, [Date] text)''')

c.execute('''CREATE TABLE IF NOT EXISTS KASICA
             ([ID] INTEGER PRIMARY KEY, [Stanje_računa] integer)''')

c.execute('SELECT * FROM KASICA')
check = c.fetchone()
if check is None:
    c.execute('INSERT INTO KASICA VALUES (?, ?);', (None, 0.0))
c.execute('SELECT * FROM OTPLATA_NA_RATE')
check = c.fetchone()
if check is None:
    c.execute('INSERT INTO OTPLATA_NA_RATE VALUES (?, ?, ?, ?, ?);', (None, "Test1", 600, "0/2", "12/08/2021"))
    c.execute('INSERT INTO OTPLATA_NA_RATE VALUES (?, ?, ?, ?, ?);', (None, "Test2", 600, "0/3", "12/08/2021"))
    c.execute('INSERT INTO OTPLATA_NA_RATE VALUES (?, ?, ?, ?, ?);', (None, "Test3", 600, "0/4", "12/08/2021"))
    c.execute('INSERT INTO OTPLATA_NA_RATE VALUES (?, ?, ?, ?, ?);', (None, "Test4", 600, "0/5", "12/08/2021"))
    c.execute('INSERT INTO OTPLATA_NA_RATE VALUES (?, ?, ?, ?, ?);', (None, "Test5", 600, "0/6", "12/08/2021"))
# Save (commit) the changes
conn.commit()


class FinancialCalc:
    def __init__(self, master):
        self.lista_opisa_rata = list()
        self.dict_for_buttons = dict()

        # Start screen define:
        self.master = master
        self.master.title("Test")
        self.master.geometry("300x300")
        self.master.resizable(False, False)

        self.otplata_na_rate_button = Button(master, text="payment in installments",
                                             command=self.otplata_na_rate_deiconify)
        self.otplata_na_rate_button.place(x=95, y=155)

        #   Otplata_na_rate TopLevel - definiranje
        self.onr_top = Toplevel()
        self.onr_top.withdraw()
        self.onr_top.protocol("WM_DELETE_WINDOW", lambda: (self.master.deiconify(), self.onr_top.withdraw()))
        self.onr_top.title("Test")
        self.onr_label = Label(self.onr_top, text="List of payments:", font=("Helvetica", 11, "underline", "bold"))
        self.onr_opis_label = Label(self.onr_top, text="Payment description:", font=("Helvetica", 11, "underline", "bold"))
        self.onr_oznacena_rata_label = Label(self.onr_top, text="Installment description:", font=("Helvetica", 11))
        self.onr_broj_rata_label = Label(self.onr_top, text="Installments:", font=("Helvetica", 11))
        self.onr_iznos_rate_label = Label(self.onr_top, text="Value:", font=("Helvetica", 11))
        self.onr_datum_isplate_label = Label(self.onr_top, text="Final payment:", font=("Helvetica", 11))

        self.onr_oznacena_rata_txt = Label(self.onr_top, text="", font=("Helvetica", 11))
        self.onr_broj_rata_txt = Label(self.onr_top, text="", font=("Helvetica", 11))
        self.onr_iznos_rate_txt = Label(self.onr_top, text="", font=("Helvetica", 11))
        self.onr_datum_isplate_txt = Label(self.onr_top, text="", font=("Helvetica", 11))

        self.onr_pl_pojed_btn = Button(self.onr_top, text="Pay selected", command=self.pay_selected)

    def pay_selected(self):
        p_description = self.onr_oznacena_rata_txt.cget("text")
        num_of_installments = self.onr_broj_rata_txt.cget("text").split("/")
        if int(num_of_installments[0])+1 >= int(num_of_installments[1]):
            c.execute('DELETE FROM OTPLATA_NA_RATE WHERE Opis = ?', (p_description,))
            conn.commit()
            btn_to_del = self.dict_for_buttons[p_description]
            btn_to_del.destroy()
            self.dict_for_buttons.pop(p_description)
            self.lista_opisa_rata.clear()

        else:
            target_3_novo = str(int(num_of_installments[0])+1) + "/" + num_of_installments[1]
            c.execute('UPDATE OTPLATA_NA_RATE SET Broj_rata = ? WHERE Opis = ?', (target_3_novo, p_description,))
            conn.commit()
            self.get_description(p_description)

    def get_description(self, opis):
        c.execute('SELECT * FROM OTPLATA_NA_RATE WHERE Opis=?;', (opis,))
        for x in c:
            dodaj_godinu = 0
            self.onr_oznacena_rata_txt.config(text=x[1])
            self.onr_iznos_rate_txt.config(text=str(x[2]) + " kn")
            self.onr_broj_rata_txt.config(text=x[3])
            datum_racunanje = int(x[4].split("/")[1]) + int(x[3].split("/")[1])
            while datum_racunanje > 12:
                datum_racunanje -= 12
                dodaj_godinu += 1
            datum_isplate = str(datum_racunanje) + "/" + str(int(x[4].split("/")[2])+dodaj_godinu)
            self.onr_datum_isplate_txt.config(text=datum_isplate)

    def otplata_na_rate_deiconify(self):
        # Otplata_na_rate TopLevel - define window:
        self.master.withdraw()
        self.onr_top.deiconify()
        self.onr_label.grid(row=0, columnspan=3, sticky="NESW")
        self.onr_opis_label.grid(row=0, column=5, sticky="NESW")
        self.onr_oznacena_rata_label.grid(row=1, column=4, padx=5, sticky="E")
        self.onr_broj_rata_label.grid(row=2, column=4, padx=5, sticky="E")
        self.onr_iznos_rate_label.grid(row=3, column=4, padx=5, sticky="E")
        self.onr_datum_isplate_label.grid(row=4, column=4, padx=5, sticky="E")

        self.onr_oznacena_rata_txt.grid(row=1, column=5, padx=5, sticky="NSWE")
        self.onr_broj_rata_txt.grid(row=2, column=5, padx=5, sticky="NSWE")
        self.onr_iznos_rate_txt.grid(row=3, column=5, padx=5, sticky="NSWE")
        self.onr_datum_isplate_txt.grid(row=4, column=5, padx=5, sticky="NSWE")

        c.execute('SELECT Opis FROM OTPLATA_NA_RATE')
        for opis in c:
            self.lista_opisa_rata.append(opis[0])
        column = 0
        row = 1
        for opis in self.lista_opisa_rata:
            # Append function to button
            function = lambda x=opis: self.get_description(x)
            rata_button = Button(self.onr_top, text=opis, width=10, command=function)
            rata_button.grid(row=row, column=column, padx=5, pady=5)
            self.dict_for_buttons[opis] = rata_button
            column += 1
            if column == 3:
                row += 1
                column = 0

        #   Define placement of Button widget - created with loop
        if row < 5:
            row = 5
        if row >= 5:
            row += 1

        self.onr_pl_pojed_btn.grid(row=row, column=5, padx=2, pady=5)

        x = self.master.winfo_x()
        y = self.master.winfo_y()
        self.onr_top.geometry(f"+{x}+{y}")


root = Tk()
my_gui = FinancialCalc(root)
root.mainloop()

简化测试代码 #

from tkinter import *

root = Tk()

toplvl = Toplevel()
toplvl.withdraw()
toplvl.protocol("WM_DELETE_WINDOW", lambda: (root.deiconify(), toplvl.withdraw()))
button_id = dict()


def btn_destroy():
    picked_btn = str(lbl_picked_btn.cget("text").split(":")[1]).rstrip()
    if picked_btn != "":
        txt = int(lbl.cget("text").split("/")[0]) + 1
        lbl.config(text=str(txt) + "/3")
        if txt == 3:
            btn_to_del = button_id[int(picked_btn)]
            btn_to_del.destroy()
            lbl.config(text="0/3")


def btn_pick(x):
    lbl_picked_btn.config(text="Button picked:"+str(x))


lbl_desc = Label(toplvl, text="Pick button and click Destroy 3 times to destroy it", font=("Helvetica", 11))
lbl_desc.grid(row=0, columnspan=4)
lbl_picked_btn = Label(toplvl, text="Button picked:", font=("Helvetica", 11))
lbl_picked_btn.grid(row=1, column=1, columnspan=2)
btn_d = Button(toplvl, width=10, text="Destroy", command=btn_destroy)
btn_d.grid(row=1, column=0)
lbl = Label(toplvl, text="0/3", font=("Helvetica", 11))
lbl.grid(row=1, column=3)


row = 2
column = 0
for i in range(5):
    function = lambda x=i: btn_pick(x)
    btn = Button(toplvl, width=10, text=str(i), command=function)
    btn.grid(row=row, column=column)
    button_id[i] = btn
    column += 1


def top():
    root.withdraw()
    toplvl.deiconify()


start_btn = Button(root, text="Start", command=top)
start_btn.pack()


root.mainloop()

核心问题原因 #

1. 每次打开子窗口的时候，都没有先销毁上一次生成的旧按钮，也没有清空存储按钮的字典和列表，导致旧按钮残留和新创建的按钮叠加显示。
2. 只有删除按钮的时候才清空lista_opisa_rata列表，正常退出子窗口再进入时，会把上一次的列表数据和新从数据库读取的数据叠加，导致重复创建按钮。

具体修改步骤 #

1. 修改otplata_na_rate_deiconify方法，在读取数据库创建新按钮之前，先销毁所有旧按钮、清空存储结构：

def otplata_na_rate_deiconify(self):
    # 先销毁所有旧的按钮
    for btn in self.dict_for_buttons.values():
        btn.destroy()
    # 清空存储结构
    self.dict_for_buttons.clear()
    self.lista_opisa_rata.clear()

    # 后面保留你原来的代码不变
    self.master.withdraw()
    self.onr_top.deiconify()
    # ... 剩下的原有代码不变

2. 删除pay_selected方法里多余的清空逻辑，把self.lista_opisa_rata.clear()这行删掉即可，不需要在这里清空列表，统一在打开子窗口的时候处理即可。

修改完成后再测试，重复按钮的问题就会消失，每次打开子窗口都会按照最新的数据库数据生成按钮。

内容的提问来源于stack exchange，提问作者Freezy