Qt for Python (PySide/Shiboken)

I’d say declare the signal with in the class definition with propertyNameChanged = Signal(parameter_type) and explicitly emit it in the property setter, if the new value differs from the old. That's plain and obvious when reading the code, and IDEs do find the signal usage. Now, there's a clash between Qt's name convention for change signals (using camelCase, like valueChanged), and Python, using snake_case, for example value_changed. PEP8 and related style guildes aren't set in stone, so I’d say, take the choice with the highest consistency