PyQt5报错：Destroyed while thread is still running

import sys
import time

from PyQt5.QtWidgets import QApplication, QPushButton, QDateTimeEdit, QWidget, QVBoxLayout
from PyQt5.QtCore import pyqtSignal, pyqtBoundSignal, QThread
import window2


class Window(QWidget):
	def __init__(self):
		super(Window, self).__init__()

		self.setWindowTitle("window1")
		self.countButton = QPushButton()
		self.dateTimeEdit = QDateTimeEdit()

		self.button = QPushButton()
		# self.button.clicked.connect(self.a)

		self.vLayout = QVBoxLayout(self)
		self.vLayout.addWidget(self.countButton)
		self.vLayout.addWidget(self.dateTimeEdit)
		self.vLayout.addWidget(self.button)

		#  countSignal = signal()
		#  countSignal.start()

        # 加self即可，具体原因不清楚
        #  self.countSignal = signal()
        #  self.countSignal.start()

class signal(QThread):
	countSignal: pyqtBoundSignal
	countSignal = pyqtSignal(int)

	def __init__(self):
		super(signal, self).__init__()
		self.number = 0

	def run(self):
		while 1:
			print(self.number)
			self.countSignal.emit(self.number)
			time.sleep(1)
			self.number += 1


if __name__ == "__main__":
	app = QApplication(sys.argv)
	window = Window()
	window.show()
	sys.exit(app.exec_())