无法在Pyqt5上保存我的窗口的大小和位置

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow
from PyQt5.QtCore import QSettings

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()

        # 读取配置文件中保存的大小和位置信息
        settings = QSettings('config.ini', QSettings.IniFormat)
        self.resize(settings.value('size', self.size()))
        self.move(settings.value('pos', self.pos()))

    def closeEvent(self, event):
        # 在窗口关闭事件中保存当前窗口的大小和位置信息
        settings = QSettings('config.ini', QSettings.IniFormat)
        settings.setValue('size', self.size())
        settings.setValue('pos', self.pos())

        super().closeEvent(event)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    mainWindow = MainWindow()
    mainWindow.show()
    sys.exit(app.exec_())