Pyqt5 QTableWidget right click

Question

When I right click on the QTableWidget, I want to show Copy and Quit menu. When I run the following codes I get "TypeError: connect () failed between customContextMenuRequested (QPoint) and __context_menu ()" error. What could be the reason for this error? How can I fix this?

from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtCore import Qt, QPoint, pyqtSlot
class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(800, 600)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.name_table = QtWidgets.QTableWidget(self.centralwidget)
        self.name_table.setGeometry(QtCore.QRect(190, 180, 256, 192))
        self.name_table.setObjectName("name_table")
        self.name_table.setColumnCount(1)
        self.name_table.setRowCount(1)
        item = QtWidgets.QTableWidgetItem()
        self.name_table.setVerticalHeaderItem(0, item)
        item = QtWidgets.QTableWidgetItem()
        self.name_table.setHorizontalHeaderItem(0, item)
        item = QtWidgets.QTableWidgetItem()
        self.name_table.setItem(0, 0, item)
        self.name_table.setContextMenuPolicy(Qt.CustomContextMenu)
        self.name_table.customContextMenuRequested.connect(self.__context_menu)

        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 22))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        item = self.name_table.verticalHeaderItem(0)
        item.setText(_translate("MainWindow", "First"))
        item = self.name_table.horizontalHeaderItem(0)
        item.setText(_translate("MainWindow", "Name"))
        __sortingEnabled = self.name_table.isSortingEnabled()
        self.name_table.setSortingEnabled(False)
        item = self.name_table.item(0, 0)
        item.setText(_translate("MainWindow", "Book"))
        self.name_table.setSortingEnabled(__sortingEnabled)

    # @pyqtSlot('QPoint')
    @pyqtSlot(QPoint)
    def __context_menu(self, position):
        menu = QMenu()
        copy_action = menu.addAction("Copy")
        quit_action = menu.addAction("Quit")
        action = menu.exec_(self.table.mapToGlobal(position))
        if action == quit_action:
            qApp.quit()
        elif action == copy_action:
            print("copy...")


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())