def app(self):
self.btn1.close()
self.btn2.close()
self.btn3.close()
self.lbl1.close()
self.btn1 = QPushButton(self)
self.btn1.setMouseTracking(True);
self.btn1.setText("Текст")
self.btn1.resize(350, 200)
self.btn1.move(-40, 1550)