tkinter在情节之后立即关闭

Question

我正在使用TKINTER创建一个接口来绘制数据库的信号。我正在使用Python 3.8和Pycharm 2021.2.1。

该界面应该打开另一个窗口（从顶部的Menubar）打开所有数据文件索引，从那里选择一个数据索引时，将在主窗口上绘制一个数据索引。问题是在图完成后立即mainloop结束。我可以看到在调试过程中实际上在画布上绘制的图，所以我知道它是绘制的，但是之后我不明白为什么它关闭了mainloop。

没有错误消息。

主窗口不应该在情节之后关闭。

import os
import random
import sys

import scipy.signal as signal
import tkinter as tk
from tkinter import ttk

import numpy as np
import re
import scipy.io as sio

from matplotlib import pyplot as plt, image as mpimg
from matplotlib.backends._backend_tk import NavigationToolbar2Tk
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
from matplotlib.cm import ScalarMappable
from matplotlib.figure import Figure

import tools.patient
import tools.biosemi
import tools.signal_avg
import tools.ecg_tools

import platform
import time
from tkinter.filedialog import askopenfilename


class main_interface():

    def __init__(self):

        print(platform.python_version())

        # region init
        if re.split('-', platform.platform())[0] == 'Windows':
            self.root_path = 'S:'
        elif re.split('-', platform.platform())[0] == 'macOS':
            self.root_path = '/Volumes/Signal'


        # region Main window
        self.root = tk.Tk()
        self.root.wm_title("Embedding in Tk")
        self.root.geometry("1000x750")

        self.root.columnconfigure(tuple(range(42)), weight=1)
        self.root.rowconfigure(tuple(range(34)), weight=1)

        self.root.protocol("WM_DELETE_WINDOW", lambda: _quit(self.root))


        menubar = tk.Menu(self.root, tearoff=False)
        filemenu = tk.Menu(menubar, tearoff=0)
        filemenu.add_command(label="Load pickle", command=lambda: popup_load_BS(self, "Load pickle"))
        menubar.add_cascade(label="File", menu=filemenu)
        # endregion

        # region Tabs menu
        self.tabsystem = ttk.Notebook(self.root)

        tab1 = tk.Frame(self.tabsystem)

        self.tabsystem.add(tab1, text='Raw Data')
        self.tabsystem.grid(row=1, column=0, rowspan=32, columnspan=42, sticky='news')


        self.root.config(menu=menubar)
        # endregion

        ############################################### region Tab 1 : Raw Data ###############################################
        tab1.columnconfigure(tuple(range(40)), weight=1)
        tab1.rowconfigure(tuple(range(30)), weight=1)

        fig = Figure()
        self.raw_data_ax = fig.add_subplot(111)

        self.raw_data_canvas = FigureCanvasTkAgg(fig, master=tab1)  # A tk.DrawingArea.
        self.raw_data_canvas.draw()
        self.raw_data_canvas.get_tk_widget().grid(row=1, column=1, columnspan=39 - 1, rowspan=18 - 1, sticky='news')

        ###############    TOOLBAR    ###############
        toolbarFrame = tk.Frame(master=tab1)
        toolbarFrame.grid(row=30, column=0, columnspan=39, sticky='sw')
        toolbar = NavigationToolbar2Tk(self.raw_data_canvas, toolbarFrame)

        self.zoom_value = tk.IntVar(toolbarFrame)
        toolbar.children['!checkbutton2'].config(variable=self.zoom_value, onvalue=1, offvalue=0)


        self.root.mainloop()


####################### region function for raw data tab #############################


def popup_load_BS(self, txt):
    def select_BS(self, event, window, txt, tree):

        item = tree.selection()
        # print(item)
        selection = tree.item(item)['values'][0]
        # print(selection)
        msg = f'Load {selection}?'
        res = tk.messagebox.askquestion('Load BS Data', msg)

        if res == 'yes':
            if txt == "Load raw bdf":
                print('BDF loaded ')
            elif txt == "Load pickle":
                print('Pickle loaded')
            window.quit()
            window.destroy()
            # plot data

            l = [random.randint(0, 10) for index in range(100)]
            self.raw_data_ax.plot(l)
            self.raw_data_canvas.draw()

            print('plotted')

    popup_root = tk.Toplevel()
    popup_root.grab_set()
    popup_root.columnconfigure(tuple(range(1)), weight=1)
    popup_root.rowconfigure(tuple(range(1)), weight=1)
    popup_root.geometry('1000x500')

    tree = ttk.Treeview(popup_root, column=("c1"), show='headings', height=1, selectmode="browse")

    tree.column("# 1", anchor='center')
    tree.heading("# 1", text="BS")
    for i in range(1,10):
        tree.insert('', i, values=('BS00'+str(i)))

    tree.grid(row=0, column=0, sticky='news')

    scroll = ttk.Scrollbar(popup_root, orient="vertical", command=tree.yview)
    scroll.grid(row=0, column=1, sticky='news')
    tree.configure(yscrollcommand=scroll.set)



    # THE ISSUE SEEMS TO BE HERE
    load_button = tk.Button(master=popup_root, text="Load")
    load_button.config(command=lambda: select_BS(self, [], popup_root, txt,tree))
    load_button.grid(row=1, column=0, columnspan=2, sticky='news')

    tree.bind("<Double-1>", lambda event: select_BS(self, event, popup_root, txt, tree))

def _quit(root):
    root.quit()  # stops mainloop
    root.destroy()  # this is necessary on Windows to prevent
                    # Fatal Python Error: PyEval_RestoreThread: NULL tstate


# endregion

if __name__ == '__main__':

    BS_data = main_interface()
    print('mainloop ended')
    # BS_data.mainloop()

该问题似乎是在代码的一部分附近，其中通过按 load 按钮或使用双击绑定到数据索引（就在_quit之前功能）