Qt for Python (PySide/Shiboken)

As I have not much experience with this and the information seems kinda voodoo I was looking up the ALL PySide2 examples for instances of @QtCore.Slot decorators. First ones I found were all QtQuick and QML based and indeed: There is the type specified and these ones actually break when the decorator is not correct 👍 (the declarative/extending/chapter3-bindings/bindings.py one has a Slot as well but actually the decorator is not needed there. The whole function is not used/needed in this example) Now any other occurrences: All these work without the @QtCore.Slot decorator: * external/matplotlib/widget_3dplot.py * external/opencv/webcam_pattern_detection.py - (super funny example! :D) * external/scikit/staining_colors_separation.py * installer_test/hello.py * opengl/grabber.py - mentions Slots in function args but does not use a decorator, works * opengl/hellogl.py - uses ancient self.connect(.. SLOT("setValue(int)"))-style but works with modern slider.valueChanged.connect(setterSlot) right away * sql/books/bookwindow.py * tutorial/t7.py - t14.py * widgets/codeeditor/codeeditor.py * widgets/state-machine/trafficlight.py * widgets/systray/main.py * widgets/threads/thread_signals.py This is the only other example where it needs to be set: * webchannel/standalone - core.py: _emit_send_text does NOT need the Slot decorator but receiveText indeed DOES! - display.py - works without - websocketclientwrapper.py - works without So I'd conclude: whenever a method is directly connected within the python code there is no need for the Slot decorator. Whenever a connection is implied and handled outside of python a Slot decorator is needed.