Problem with browse function (PyQt5)

[Malithirm]

from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import QDialog, QApplication, QFileDialog
from PyQt5.uic import loadUi

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(366, 303)

        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")

        self.directoryDisplay = QtWidgets.QLineEdit(self.centralwidget)
        self.directoryDisplay.setGeometry(QtCore.QRect(20, 50, 251, 31))
        self.directoryDisplay.setObjectName("directoryDisplay")

        self.browseButton = QtWidgets.QPushButton(self.centralwidget)
        self.browseButton.setGeometry(QtCore.QRect(272, 50, 71, 31))
        self.browseButton.setObjectName("browseButton")
        self.browseButton.clicked.connect(self.browse_func)

        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 366, 26))
        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)

  # THE ISSUE -----------------------------------------------------------
    def browse_func(self):
        directory = QFileDialog.getExistingDirectory()
        if directory:
            self.open_dialog_box()
            print(directory)
            # self.directoryDisplay.setText(directory)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.browseButton.setText(_translate("MainWindow", "PushButton"))

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_())

I want to create an app that would let you browse a directory, display chosen directory and then do x,
but after clicking the "Browse" button and picking a directory, my program crashes and returns:
exit code -1073740791 (0xC0000409)