11 PyQt5 QMenuBar Python GUI Programming With PyQt5
У вашего броузера проблема в совместимости с HTML5
Source Codes:
https://codeloop.org/category/pyqt5/
Menu Bar In PyQt5
A menubar is a common part of a GUI application. It is a group of commands located in various menus. (Mac OS treats menubars differently. To get a similar outcome, we can add the following line: