Pyqt5- QMessageBox is appearing blank & program getting crashed

[ShubhamGupta123]

I am trying to run a code to load dataframe into a sql server using PyQT5 and also at the same time showing a "Please wait" pop up while data is being loaded in DB. I am utilizing QThread for the same. If there is some error then QMessageBox shows the error to the user. But my program is crashing with Message Box appearing blank. I am attaching both code and error snippet.Error Snippet

from functools import partial
from PyQt5 import QtCore, QtGui, QtWidgets
import configparser
import pyodbc


def ConfigSection(section,Config):
    dict1 = {}
    options = Config.options(section)
    for option in options:
        try:
            dict1[option] = Config.get(section,option)
        except:
            dict1[option] = None
    return dict1


class DatabaseWorker(QtCore.QObject):
    started = QtCore.pyqtSignal()
    finished = QtCore.pyqtSignal()
    message = QtCore.pyqtSignal(object)
    msg = ""

    @QtCore.pyqtSlot()
    def writeToDatabase(self, final_pivot):
        self.started.emit()
        Config = configparser.ConfigParser(interpolation=None)
        try:
            config_file = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'config.ini')
            Config.read_string(open(config_file).read())
            config_values = ConfigSection("Global", Config)
            driver = config_values.get('driver')
            server = config_values.get('server')
            database = config_values.get('database')
            username = config_values.get('username')
            password = config_values.get('password')
            con_str = ("Driver={" + driver + "};"
                                             "Server=" + server + ";"
                                                                  "Database=" + database + ";"
                                                                                           "UID=" + username + ";"
                                                                                                               "PWD=" + password + ";")
            cnxn = pyodbc.connect(con_str)
            cursor = cnxn.cursor()
            for i, row in final_pivot.iterrows():
                sql = "INSERT INTO dbo.[FPP_Cleansed_MarketData] (ID,Region,Geography,Category,Company,Year,Adjusted_Sales,Sales_Units,Unit_Type)  VALUES (" + "?," * (
                        len(row) - 1) + "?)"
                cursor.execute(sql, tuple(row))
            cnxn.commit()
        except pyodbc.Error as ex:
            sqlstate = ex.args[0]
            if sqlstate == '28000':
                msg = "Error: Error while logging in. Please check login credentials"
                self.message.emit(msg)
credentials")
                return -1
            elif sqlstate == '23000':
                msg = "Error: Trying to insert duplicate ID"
                self.message.emit(msg)
                return -1
            else:
                msg = "Error: Error encountered while inserting records into Data Warehouse"
                self.message.emit(msg)
                return -1
        finally:
            self.finished.emit()


class Windows_GUI(QtWidgets.QMainWindow):
    def __init__(self, df):
        QtWidgets.QMainWindow.__init__(self)
        self.__threads = []
        self.thread = QtCore.QThread(parent=self)
        self.__threads.append(self.thread)
        self.thread.start()
        self.m_database_worker = DatabaseWorker()
        self.m_database_worker.moveToThread(self.thread)
        self.m_database_worker.started.connect(self.start_animation)
        self.m_database_worker.message.connect(self.show_message)
        wrapper = partial(self.m_database_worker.writeToDatabase,df)
        QtCore.QTimer.singleShot(0, wrapper)


    @QtCore.pyqtSlot()
    def start_animation(self):
        gif_path = "loading.gif"
        self.loading_window = QtWidgets.QDialog()
        self.loading_window.setWindowFlags(QtCore.Qt.SplashScreen)
        self.loading_window.setAttribute(QtCore.Qt.WA_DeleteOnClose)
        movie = QtGui.QMovie(gif_path, cacheMode=QtGui.QMovie.CacheAll)
        movie_label = QtWidgets.QLabel(alignment=QtCore.Qt.AlignCenter)
        movie_label.setFixedSize(100, 75)
        movie_label.setMovie(movie)
        text_label = QtWidgets.QLabel('Data is getting loaded into Data Warehouse. Please wait...')
        text_label.setFont(QtGui.QFont('Arial',11))
        vbox = QtWidgets.QHBoxLayout(self.loading_window)
        vbox.addWidget(movie_label)
        vbox.addWidget(text_label)
        self.m_database_worker.finished.connect(self.close_window)
        movie.start()
        self.setVisible(False)
        self.loading_window.show()

    def show_message(self,msg):
        try:
            self.msg_box = QtWidgets.QMessageBox()
            self.msg_box.setWindowTitle('Error')
            self.msg_box.setIcon(QtWidgets.QMessageBox.Critical)
            self.msg_box.information(self, 'Message', msg)
            #self.msg_box.setText("Hello Rock the Brahma Bull")
            self.msg_box.move(self.frameGeometry().center())
            self.msg_box.exec_()
        except Exception as e:
            print(e)

    def close_window(self):
        for thread in self.__threads:
            thread.quit()
            thread.wait()
        self.close()


if __name__ == "__main__":
    import sys
    import pandas as pd
    app = QtWidgets.QApplication(sys.argv)
    df = pd.read_excel('test.xlsx')
    df['ID'] = ['Project_id_' + str(i) for i in range(len(df))]
    df = df[['ID', 'Regions', 'Geographies', 'Categories', 'Companies', 'Year', 'Sales', 'Sales_Unit','Currency Conversion']]
    w = Windows_GUI(df)
    w.show()
    sys.exit(app.exec_())

[SGaist]

Hi and welcome to devnet,

What is the back trace of your crash ?