[mkempe]

Qt uses slots and signals to control messaging between threads (e.g. the UI and the workers).

The Python binding to Qt is good, but it is auto-generated (from C++) and some of it shows up as non-Pythonic mechanisms or conventions.

[amyjess]

Newer versions of PyQt have replaced the magic strings with a system that's much more Pythonic, using decorators and OOP.

I guess the author just wanted to keep backwards compatibility with old versions (or isn't aware of the change).

Edit: If anyone's interested, here's the new syntax: http://pyqt.sourceforge.net/Docs/PyQt4/new_style_signals_slo...

[pyskell]

Thanks for this. I had no idea a different mechanism existed.

[mkempe]

is PySide2 also getting that new system?

[amyjess]

Looks like it: https://wiki.qt.io/Signals_and_Slots_in_PySide