PyQt5 window.close()不会关闭窗口，但window.open()可以正常工作

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow

app = QApplication(sys.argv)
window = QMainWindow()
window.show()
sys.exit(app.exec_())

class ChildWindow(QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.parent = parent

    def closeEvent(self, event):
        if self.parent:
            self.parent.close()
        event.accept()

# 在主窗口中创建子窗口
child_window = ChildWindow(window)
child_window.show()

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.timer = QTimer(self)
        self.timer.timeout.connect(self.update)
        self.timer.start(1000)

    def closeEvent(self, event):
        self.timer.stop()
        event.accept()

window = MainWindow()
window.show()

try:
    window.close()
except Exception as e:
    print(f"Error closing window: {e}")

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow
from PyQt5.QtCore import QTimer

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.timer = QTimer(self)
        self.timer.timeout.connect(self.update)
        self.timer.start(1000)

    def closeEvent(self, event):
        self.timer.stop()
        event.accept()

app = QApplication(sys.argv)
window = MainWindow()
window.show()
sys.exit(app.exec_())