如何在 PyQt5 中创建嵌套菜单？

试试这样：

import sys
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton, QMenu, QVBoxLayout

class AppDemo(QWidget):
    def __init__(self):
        super().__init__()

        states_cities = [
            {'Список слов': ['Hello', 'World', 'How you been', 'Good to see you']},
            {'Список языков': ['Английский', 'Французский', 'Испанский']},
            'Help',
            'Exit'
        ]

        menu = QMenu()
        menu.triggered.connect(lambda x: print(x.text()))
        self.add_menu(states_cities, menu)

        btn = QPushButton('My Menu', self)
        btn.setMenu(menu)

    def add_menu(self, data, menu_obj):
        if isinstance(data, dict):
            for k, v in data.items():
                sub_menu = QMenu(k, menu_obj)
                menu_obj.addMenu(sub_menu)
                self.add_menu(v, sub_menu)
        elif isinstance(data, list):
            for element in data:
                self.add_menu(element, menu_obj)
        else:
            action = menu_obj.addAction(data)
            action.setIconVisibleInMenu(False)


if __name__ == '__main__':
    app = QApplication(sys.argv)        
    demo = AppDemo()
    demo.show()
    sys.exit(app.exec_())

或像这样：

import sys
from PyQt5.Qt import *


class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()

        bar = self.menuBar()
        self.file = bar.addMenu("File")
        self.file.addAction("New")

        save = QAction("Save", self)
        save.setShortcut("Ctrl+S")
        self.file.addAction(save)

        edit = self.file.addMenu("Edit")
        edit.addAction("copy")
        edit.addAction("paste")

        quit = QAction(QIcon("D:/_Qt/__Qt/img/exit.png"), "Quit",self)
        quit.setShortcut('Ctrl+Q')
        quit.triggered.connect(qApp.quit)
        self.file.addAction(quit)

        self.file.triggered[QAction].connect(self.processtrigger)     

        self.centralWidget = QWidget()
        self.setCentralWidget(self.centralWidget)
        self.combo = QComboBox()
        self.combo.addItems(["option1", "option2", "option3", "option4"])
        layout = QVBoxLayout(self.centralWidget)
        layout.addWidget(self.combo)

    def processtrigger(self, q):
        print( q.text()+" is triggered" )

    def contextMenuEvent(self, event):
        result = self.file.exec_(self.mapToGlobal(event.pos()))


if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = MainWindow()
    ex.setWindowTitle("Qmenu")
    ex.resize(350,300)
    ex.show()
    sys.exit(app.exec_())