PySide6 QTimer.timeout.connect does not work within QMainWidget, but in QApplication

Hi,

I’ve made a PySide6 GUI application with several QTimer objects within widgets.

If I execute the application with python, everything is fine. Also deployed with cx_freeze.

Now I’ve tried nuitka with following command: python.exe -m nuitka --mingw64 --standalone test.py --plugin-enable=pyside6 --plugin-enable=pylint-warnings --follow-imports

The result does not work, since the methods connected to the timers are not executed. I’ve made 2 small examples you can find at the end.

• Nuitka version, full Python version and Platform (Windows, OSX, Linux …)

  python -m nuitka --version

0.6.16.4
Python: 3.9.4 (tags/v3.9.4:1f2e308, Apr  6 2021, 13:40:21) [MSC v.1928 64 bit (AMD64)]
Executable: C:\Users\Bad\AppData\Local\Programs\Python\Python39\python.exe
OS: Windows
Arch: x86_64

• How did you install Nuitka and Python

installed via pip. No venv

• The specific PyPI names and versions

  python -m pip freeze

PySide6==6.1.3

• Also supply a Short, Self Contained, Correct, Example Not Working Example QTimer within Widget:

#%%
import sys
from PySide6.QtWidgets import QApplication, QMainWindow
from PySide6.QtCore import QTimer

class MainWidget(QMainWindow):
    def __init__(self, parent=None):
        super(MainWidget, self).__init__(parent)
        self.timer = QTimer(self) #self
        self.timer.timeout.connect(self.update)
        self.timer.start(1000)
        self.count = 0

    def update(self):
        self.count += 1
        print ("update ",self.count)
        if self.count >5:
            self.timer.stop()
            self.close()

if __name__ == "__main__":
    app = QApplication(sys.argv)
    mymain = MainWidget()
    mymain.show()
    sys.exit(app.exec())

Expected output:

>test.exe
update 1
update 2
update 3
update 4
update 5
update 6

Working Example - QTimer within QApplication:

#%%
import sys
from PySide6.QtWidgets import QApplication
from PySide6.QtCore import QTimer

class MainApp(QApplication):
    def __init__(self, parent=None):
        super(MainApp, self).__init__(parent)
        self.timer = QTimer(self) #self
        self.timer.timeout.connect(self.update)
        self.timer.start(1000)
        self.count = 0

    def update(self):
        self.count += 1
        print ("update",self.count)
        if self.count >5:
            self.timer.stop()
            self.exit()

if __name__ == "__main__":
    app = MainApp(sys.argv)
    sys.exit(app.exec())

Any idea?

Best regards Bastian

[kayhayen]

Well, that’s of course not right. I am not sure it’s a bug of yours, I am pretty sure it’s one of ours, Nuitka and/or PySide6 here, but at least you now have a workaround. I cannot work on this right away, but it seems important, and so this will be dealt with eventually.

However, thanks for the good report, and sticking with me on this. 😃

[kayhayen]

This does it for me, thank you, but I am totally confused as to what the difference could be. But once I know the bug, maybe I can tell why it was working for me with the other example.