import sys from PyQt5.QtCore import pyqtSignal, QObject from PyQt5.QtWidgets import QMainWindow, QApplication class mysignal(QObject): closeApp = pyqtSignal(list) class Example(QMainWindow): def __init__(self): super().__init__() self.c = mysignal() self.c.closeApp.connect(self.myclose) self.show() def mousePressEvent(self, event): hehe = list(range(10)) self.c.closeApp.emit(hehe) def myclose(self, mylist): print(mylist) self.close() if __name__ == '__main__': app = QApplication(sys.argv) ex = Example() sys.exit(app.exec_())