обновить кадр данных после редактирования в qTableView Python PyQt5

Question

Добрый день,

Я пытаюсь загрузить фрейм данных в PyQt5 QTableView, чтобы разрешить редактирование последнего столбца с помощью ComboBox. Как только редактирование будет завершено, распечатайте фрейм данных, чтобы я мог редактировать его дальше. Когда я нажимаю «print_data», я не могу получить обновленную модель QTableView для печати. Код можно увидеть ниже.

import sys
from PyQt5.QtWidgets import (QWidget, QLabel, QLineEdit, QTextEdit, QGridLayout, QApplication)
import pandas as pd
import numpy as np
import PyQt5 
from PyQt5.QtWidgets import QVBoxLayout, QPushButton, QGroupBox, QHBoxLayout, QMainWindow, QApplication, QLineEdit, QFileDialog,  QTableWidget,QTableWidgetItem, QTableView, QStyledItemDelegate
from PyQt5 import QtCore, QtGui, QtWidgets   
import os
from PyQt5.QtWidgets import (QWidget, QPushButton, QHBoxLayout, QVBoxLayout, QApplication)
from PyQt5.QtGui import QIcon
import re

def dataframe():
    lst = [['tom', 'reacher', 'True'], ['krish', 'pete', 'True'], 
           ['nick', 'wilson', 'True'], ['juli', 'williams', 'True']] 
    df = pd.DataFrame(lst, columns =['FName', 'LName', 'Student?'], dtype = float) 
    return df

class Delegate(QtWidgets.QItemDelegate):
    def __init__(self, owner, choices):
        super().__init__(owner)
        self.items = choices

    def createEditor(self, parent, option, index):
        self.editor = QtWidgets.QComboBox(parent)
        self.editor.currentIndexChanged.connect(self.commit_editor)
        self.editor.addItems(self.items)
        return self.editor    

    def paint(self, painter, option, index):
        value = index.data(QtCore.Qt.DisplayRole)
        style = QtWidgets.QApplication.style()
        opt = QtWidgets.QStyleOptionComboBox()
        opt.text = str(value)
        opt.rect = option.rect
        style.drawComplexControl(QtWidgets.QStyle.CC_ComboBox, opt, painter)
        QtWidgets.QItemDelegate.paint(self, painter, option, index)

    def commit_editor(self):      ####test
        editor = self.sender()
        self.commitData.emit(editor)


    def setEditorData(self, editor, index):
        value = index.data(QtCore.Qt.DisplayRole)
        num = self.items.index(value)
        editor.setCurrentIndex(num)

    def setModelData(self, editor, model, index):
        value = editor.currentText()
        model.setData(index, value, QtCore.Qt.EditRole)

    def updateEditorGeometry(self, editor, option, index):
        editor.setGeometry(option.rect)


class PandasModel(QtCore.QAbstractTableModel):
    def __init__(self, data, parent=None):
        QtCore.QAbstractTableModel.__init__(self, parent)
        self._data = data

    def rowCount(self, parent=None):
        return self._data.shape[0]

    def columnCount(self, parent=None):
        return self._data.shape[1]

    def flags(self, index):
        return QtCore.Qt.ItemIsEditable | QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable

    def data(self, index, role=QtCore.Qt.DisplayRole):
        if index.isValid():
            if role == QtCore.Qt.DisplayRole:
                return str(self._data.iloc[index.row(), index.column()])
        return None

    def headerData(self, col, orientation, role):
        if orientation == QtCore.Qt.Horizontal and role == QtCore.Qt.DisplayRole:
            return self._data.columns[col]
        return None

    def setData(self, index, value, role=QtCore.Qt.EditRole):
        self._data[index.row()][index.column()] = value
        self.dataChanged.emit(index, index, (QtCore.Qt.DisplayRole, ))
        return True 

class MyWindow(QWidget):

    def __init__(self):
        super().__init__()
        self.setGeometry(300, 200 ,600, 400)
        self.setWindowTitle('Test')
        self.initUI()


    def show_data(self):
        choices = ['True', 'False']
        self.model = PandasModel(dataframe())
        self.table_data.setModel(self.model)                            
        self.table_data.setItemDelegateForColumn(2, Delegate(self,choices))
        ##make combo boxes editable with a single-click:
        for row in range(5):  
            self.table_data.openPersistentEditor(self.model.index(row, 2))

    def print_data(self):
        print(self.table_data.model()._data)

    def initUI(self):

        welcom = QLabel('Welcome to my app!')

        self.btn_print_data = QPushButton('print data')
        self.btn_print_data.clicked.connect(self.print_data)  ##test

        self.btn_show_table = QPushButton('show data')
        self.btn_show_table.clicked.connect(self.show_data)

        self.table_data = QTableView()
        #self.table_result = QTableView()

        hbox1 = QHBoxLayout()
        hbox1.addWidget(welcom)


        vbox2 = QVBoxLayout()
        vbox2.addWidget(self.btn_show_table)
        vbox2.addWidget(self.btn_print_data) ####test

        vbox3 = QVBoxLayout()
        vbox3.addWidget(self.table_data)
        #vbox3.addWidget(self.table_result)

        hbox2 = QHBoxLayout()
        hbox2.addLayout(vbox2)
        hbox2.addLayout(vbox3)

        vbox1 = QVBoxLayout()
        vbox1.addLayout(hbox1)
        vbox1.addLayout(hbox2)

        self.setLayout(vbox1)
        self.show()


if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = MyWindow()
    sys.exit(app.exec_())