[PyQt] bug or expected?

[Phil Thompson]

On 27 Dec 2016, at 8:24 pm, oliver <oliver.schoenborn at gmail.com> wrote:
> 
> from PyQt5.QtCore import QObject, pyqtSlot, Qt, pyqtSignal
> 
> class MyObj(QObject):
>     sig_test = pyqtSignal()
> 
> class Listener(QObject):
>     @pyqtSlot()
>     def meth(self):
>         pass
> 
>     # @pyqtSlot()
>     def meth2(self):
>         pass
> 
> obj = MyObj()
> obs = Listener()
> 
> def test_no_connections(slot):
>     assert obj.receivers(obj.sig_test) == 0
> 
>     obj.sig_test.connect(slot, Qt.UniqueConnection)
>     assert obj.receivers(obj.sig_test) == 1
> 
>     obj.sig_test.disconnect(slot)
>     assert obj.receivers(obj.sig_test) == 0
> 
> test_no_connections(obs.meth)
> test_no_connections(obs.meth)
> 
> test_no_connections(obs.meth2)
> test_no_connections(obs.meth2)  # FAILS 
> 
> Last line fails because meth2 was not decorated with pyqtSlot. Is this expected or a bug?

It's only happening because you don't have an event loop (which is not the usual circumstance). However I can change things so that it will work in this case.

> Related to this, the exception on a unique connection is completely different if the method is decorated. Using the same code as above (but without the test_no_connections stuff): 
> 
> def test_unique_connection(slot, str_exc):
>     obj.sig_test.connect(slot, Qt.UniqueConnection)
>     try:
>         obj.sig_test.connect(slot, Qt.UniqueConnection)
>     except TypeError as exc:
>         assert str(exc) == str_exc
> 
> test_unique_connection(obs.meth, 'connect() failed between MyObj.sig_test[] and meth()')
> test_unique_connection(obs.meth2, 'connection is not unique')
> 
> Shouldn't both produce an exception that says 'connection is not unique'?

Ideally but the first one is from Qt and the second (more useful one) is from PyQt.

Phil