https://stackoverflow.com/questions/51521856/avoiding-code-duplication-for-properties-in-pyside2

main.py

from PySide2.QtCore import Property, QObject, Signal, QCoreApplication, QTimer

class QtProperty(Property):
    def __init__(self, value, name='', type_=None, notify=None):
        if type_ and notify:
            super().__init__(type_, self.getter, self.setter, notify=notify)
        self.value = value
        self.name = name

    def getter(self, inst=None):
        return self.value

    def setter(self, inst=None, value=None):
        if self.value == value:
            return
        self.value = value
        getattr(inst, '%sChanged' % self.name).emit(value)

class PropertyMeta(type(QObject)):
    def __new__(mcs, name, bases, attrs):
        for key in list(attrs.keys()):
            attr = attrs[key]
            if not isinstance(attr, QtProperty):
                continue
            value = attr.value
            notifier = Signal(type(value))
            attrs[key] = QtProperty(value, key, type(value), notify=notifier)
            attrs['%sChanged' % key] = notifier
        return super().__new__(mcs, name, bases, attrs)


class BackEnd(QObject, metaclass=PropertyMeta):
    my_prop = QtProperty(False)

if __name__ == '__main__':
    import sys

    app = QCoreApplication(sys.argv)

    obj = BackEnd()
    obj.my_propChanged.connect(lambda val: print(val))

    timer = QTimer()
    timer.timeout.connect(lambda: setattr(obj, "my_prop", not getattr(obj, "my_prop")))

    timer.start(1000)
    sys.exit(app.exec_())