Pyqt5 中的定时器依赖多线程

Question

I am trying to implement a program, it consists of 2 classes, class 1 will run every 10 seconds, and class 2 will run every second, the code works fine, but when I add in the second class a graphical interface with pyqt, the程序不工作。 这是我制作的代码示例：

from threading import Thread, Event
from PyQt5 import QtWidgets
import time
import sys
import os

class class2(Thread):
    def __init__(self, event, t):
        Thread.__init__(self)
        self.t = t
        self.stopped = event

        app = QtWidgets.QApplication(sys.argv)
        #self.ui = Ui_Widgets()
        #self.ui.showFullScreen()
        sys.exit(app.exec_())
        

    def run(self):
        while not self.stopped.wait(self.t):
            print("**** class2 ****")

class class1(Thread):
    def __init__(self, event,t):
        Thread.__init__(self)
        self.stopped = event
        self.t = t

    def run(self):
        while not self.stopped.wait(self.t):
            print("**** class1 ****")

if __name__ == '__main__':
    stopFlag = Event()
    timer_10s = 10  # 10 second
    timer_1s = 1  # 1 second

    thread1 = class1(stopFlag, timer_10s)
    thread2 = class2(stopFlag, timer_1s)

    thread1.start()
    thread2.start()

    thread1.join()
    thread2.join()