如何让PyQT程序不断刷新一个小部件,始终提供最新的价值？

import sys
import time
from PyQt5.QtWidgets import QApplication, QWidget, QVBoxLayout, QLabel

class RefreshingWidget(QWidget):
    def __init__(self):
        super().__init__()

        self.initUI()

    def initUI(self):
        self.layout = QVBoxLayout()
        self.label = QLabel()

        self.layout.addWidget(self.label)
        self.setLayout(self.layout)

        self.startUpdating()

    def startUpdating(self):
        self.timer = self.startTimer(1000)  # 每秒更新一次

    def timerEvent(self, event):
        if event.timerId() == self.timer:
            current_time = time.strftime("%Y-%m-%d %H:%M:%S")
            self.label.setText(current_time)

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