how to make python Qwidget for c++ QtMainWindow?

[d_stranz]

If you are using PySide, then the PySide QWidget has a method winId() which returns a wId handle to the underlying window system window handle (like an HWnd in native Windows code).

On the C++ side, the static method QWidget::find() takes a wId as argument and returns a QWidget pointer. So this could be the solution for you.

[giseladross]

You can embed a Python-based QWidget into a C++ QMainWindow by exposing the QMainWindow's addWidget function using Python bindings. This is typically done with PySide6 or PyQt6.

Steps:
1. Expose C++ functions to Python: Use Shiboken (for PySide6) or SIP (for PyQt6) to create bindings for QMainWindow’s addWidget function.
2. Embed Python in C++: Use CPython API (Py_Initialize(), PyImport_ImportModule(), etc.) to run Python code inside C++.
3. Create Python UI Components: Design QWidget in Python and expose it to C++.
4. Load Python Widgets in C++: Use the exposed functions to add Python-based QWidget dynamically.