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  1. Qt for Python
  2. PYSIDE-2423

Signature of objects with __call__ method incorrectly inspected on signal connect

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    • Icon: Bug Bug
    • Resolution: Unresolved
    • Icon: Not Evaluated Not Evaluated
    • None
    • 6.x, 5.15.9
    • PySide
    • None
    • macOS
    • fe057b441 (dev), 7c77ccc08 (6.6), c44b7409a (6.5)

      It appears that the call signature of callable objects (i.e. objects with a _call_ method that aren't functions or bound methods) is not being correctly inspected during signalInstanceConnect. So, if they accept less arguments than the signal emits, an exception occurs during emit. This is the case with both PySide6 and PySide2, but is not the case with PyQt5/6. It does work, however, if you connect to the 

      __call__

      method directly

      Example:

      # from PyQt5.QtCore import QObject, pyqtSignal as Signal  # works
# from PyQt6.QtCore import QObject, pyqtSignal as Signal  # works
# from PySide2.QtCore import QObject, Signal              # breaks
from PySide6.QtCore import QObject, Signal                # breaks


class Emitter(QObject):
    sig = Signal(int, int)


class MyObj:
    def __call__(self, x: int):
        print(locals())


emitter = Emitter()
obj = MyObj()
emitter.sig.connect(obj)  # they ALL work if you connect to obj.__call__
emitter.sig.emit(1, 2)

      raises

      TypeError: MyObj.__call__() takes 2 positional arguments but 3 were given

        1. pyside2423.py
          0.8 kB
        For Gerrit Dashboard: PYSIDE-2423
        # Subject Branch Project Status CR V
        498332,5 WIP: Handle arguments of callables connected to signals dev pyside/pyside-setup Status: NEW -2 0

            crmaurei Cristian Maureira-Fredes
            talley Talley Lambert
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              Created:
              Updated:

                There is 1 open Gerrit change