Can I blur the background behind the qwidget "menu_pos_"?

Question

Python

I need to make the background of the "menu_pos_" block semi-transparent and blur everything behind it. while the text is left crisp this effect is commonly referred to as the frosted glass effect.



But unfortunately I was able to blur only the entire widget

import sys


from PyQt5.QtCore import (QCoreApplication, QMetaObject, QObject, QPoint,
    QRect, QSize, QUrl, Qt)
from PyQt5 import QtWidgets
from PyQt5 import QtGui
from PyQt5 import QtCore
from PyQt5.QtCore import QPropertyAnimation, QPoint

from PyQt5.QtWidgets import QGraphicsEffect

#Or

'''
from PySide2.QtCore import (QCoreApplication, QMetaObject, QObject, QPoint,
    QRect, QSize, QUrl, Qt)
from PySide2 import QtWidgets
from PySide2 import QtGui
from PySide2 import QtCore
from PySide2.QtCore import QPropertyAnimation, QPoint

from PySide2.QtWidgets import QGraphicsEffect
'''



class test_mynu(QtWidgets.QWidget):
    def __init__(self, arr="", parent=None):
        super(test_mynu, self).__init__(parent)
        self._expand = False                                # - self.__expand ; + self._expand  !!!
        #------menu_pos_block------
        self.menu_pos_block = QtWidgets.QWidget()

        blur = QtWidgets.QGraphicsBlurEffect(blurRadius=5)
        self.menu_pos_block.setGraphicsEffect(blur)


        #------menu_pos_block_layout------
        self.menu_pos_block_layout = QtWidgets.QHBoxLayout(self.menu_pos_block)
        self.menu_pos_block_layout.setObjectName(u"menu_pos_block_layout")
        #------menu_pos_label------
        self.menu_pos_label = QtWidgets.QLabel()
        self.menu_pos_label.setText(arr)
        self.menu_pos_block_layout.addWidget(self.menu_pos_label)
        #------ADD------
        lay = QtWidgets.QHBoxLayout(self)
        lay.addWidget(self.menu_pos_block)



class MainWindow(QtWidgets.QMainWindow):
    # number of radio
    def num(self):
        return 3
    def __init__(self, parent=None):
        super().__init__(parent)

        self.toggle_animations = QtCore.QSequentialAnimationGroup(self)

        #------centralwidget------
        centralwidget = QtWidgets.QWidget()
        centralwidget.setObjectName(u"centralwidget")
        self.setCentralWidget(centralwidget)
        #------layout------
        central_w_layout = QtWidgets.QGridLayout(centralwidget)
        central_w_layout.setObjectName(u"central_w_layout")
        #------Spacer------
        vs_up = QtWidgets.QSpacerItem(17, 105, QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.Expanding)
        central_w_layout.addItem(vs_up, 0, 1, 1, 1)
        hs_left = QtWidgets.QSpacerItem(327, 20, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Minimum)
        central_w_layout.addItem(hs_left, 1, 0, 1, 1)
        hs_right = QtWidgets.QSpacerItem(326, 20, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Minimum)
        central_w_layout.addItem(hs_right, 1, 2, 1, 1)
        vs_down = QtWidgets.QSpacerItem(20, 105, QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.Expanding)
        central_w_layout.addItem(vs_down, 2, 1, 1, 1)
        #------block------
        block = QtWidgets.QWidget()
        block.setObjectName(u"block")
        central_w_layout.addWidget(block, 1, 1, 1, 1)             ######
        #------layout------
        layout_block = QtWidgets.QVBoxLayout(block)
        layout_block.setObjectName(u"layout_block")
        #------menu_block------
        menu_block = QtWidgets.QWidget()
        menu_block.setObjectName(u"menu_block")
        layout_block.addWidget(menu_block)             ######
        #------menu_layout------
        menu_layout = QtWidgets.QHBoxLayout(menu_block)
        menu_layout.setObjectName(u"menu_layout")

        self.menu_but = []
        self.menu_pos = []
        self.menu_by_pos = None

        for i in range(self.num()):
            menu_pos_block = test_mynu("menu_{}".format(i))
            menu_pos_block.setObjectName("menu_pos_{}".format(i))

            self.menu_pos.append(menu_pos_block)
            self.menu_pos[i].setGeometry(QRect(menu_pos_block.width(), menu_pos_block.height(), 151, 181))
            menu_layout.addWidget(self.menu_pos[i])

        #------menu_block_but------
        self.menu_block_but = QtWidgets.QWidget()
        self.menu_block_but.setObjectName(u"menu_block_but")
        menu_layout.addWidget(self.menu_block_but)             ######
        #------menu_block_but_layout------
        menu_block_but_layout = QtWidgets.QVBoxLayout(self.menu_block_but)
        menu_block_but_layout.setObjectName(u"menu_block_but_layout")
        #------menu_but_radio------
        for i in range(self.num()):
            menu_but_radio = QtWidgets.QRadioButton('{}'.format(i))
            menu_but_radio.setObjectName("{}".format(i))
            menu_but_radio.toggled.connect(self.menu_animation)

            self.menu_but.append(menu_but_radio)
            menu_block_but_layout.addWidget(menu_but_radio)

        # Связывание меню к кнопкам и наоборот
        self.menu_by_but = dict()
        self.but_by_menu = dict()
        for i in range(self.num()):
            but = self.menu_but[i]
            menu = self.menu_pos[i]

            self.menu_by_but[menu] = but
            self.but_by_menu[but] = menu

        menu_block_content = QtWidgets.QWidget()
        menu_block_content.setObjectName(u"menu_block_content")
        menu_layout.addWidget(menu_block_content)             ######
        #------menu_content_layout------
        menu_content_layout = QtWidgets.QHBoxLayout(menu_block_content)
        menu_content_layout.setObjectName(u"menu_content_layout")
        #------menu_label------
        menu_label = QtWidgets.QLabel()
        menu_label.setText('text, text text, text')
        menu_content_layout.addWidget(menu_label)

        self.num = 0
        self.menu_pos_ter = []

    def menu_animation(self):
        self.num =self.num+1
        self.toggle_animations.clear()

        num = int(self.sender().objectName())
        self.menu_pos_ter.append(self.menu_pos[num])

        # Хитрая сортировка, что сначала вернет элемент с _expand = True
        for menu in sorted(self.menu_pos_ter, key=lambda x: x._expand):
            pos1 = QPoint(self.menu_block_but.x() - menu.width(), menu.y())
            pos2 = QPoint(self.menu_block_but.x() +self.menu_block_but.width(), menu.y())

            but = self.menu_by_but[menu]
            menu.raise_()
            self.menu_block_but.raise_()
            if but.isChecked():

                start_pos = pos1
                end_pos = pos2
            else:
                start_pos = menu.pos()
                end_pos = pos1

            anim = QPropertyAnimation(menu, b"pos")
            anim.setDuration(1000)
            anim.setStartValue(start_pos)
            anim.setEndValue(end_pos)

            self.toggle_animations.addAnimation(anim)


        if (self.num == 1) or (self.num == 3):
            self.toggle_animations.start()
            self.menu_pos_ter.clear()

        if self.num == 3 :
            self.num = 1
        print("--x--")


StyleSheet = """
#centralwidget QWidget QWidget,
#centralwidget QWidget QWidget QWidget QWidget,
#centralwidget QWidget QWidget QWidget QWidget QWidget QWidget,
#centralwidget QWidget QWidget QWidget QWidget QWidget QWidget QWidget QWidget,
#centralwidget QWidget QWidget QWidget QWidget QWidget QWidget QWidget QWidget QWidget QWidget{
background:#000;
color:#fff;
}
#centralwidget QWidget,
#centralwidget QWidget QWidget QWidget,
#centralwidget QWidget QWidget QWidget QWidget QWidget,
#centralwidget QWidget QWidget QWidget QWidget QWidget QWidget QWidget,
#centralwidget QWidget QWidget QWidget QWidget QWidget QWidget QWidget QWidget QWidget{
background:#fff;
color:#000;
}
#click_me{
background:#000;
color:#fff;
}
"""

if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    app.setStyleSheet(StyleSheet)
    w = MainWindow()
    w.resize(640, 570) #Size window
    w.show()
    sys.exit(app.exec_())

Last time when I tried to make such effect on html. I had to use js to copy the entire html code, frame it in a frame overflow: hidden; and synchronize movements with buttons.

If possible, I would like to avoid this method, as it was the wildest horror.