PyQt5: obtener el rol del elemento seleccionado en ComboBox

# importing libraries
from PyQt5.QtWidgets import * 
from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import * 
from PyQt5.QtCore import * 
import sys
  
  
class Window(QMainWindow):
  
    def __init__(self):
        super().__init__()
  
        # setting title
        self.setWindowTitle("Python ")
  
        # setting geometry
        self.setGeometry(100, 100, 600, 400)
  
        # calling method
        self.UiComponents()
  
        # showing all the widgets
        self.show()
  
    # method for widgets
    def UiComponents(self):
  
        # creating a combo box widget
        self.combo_box = QComboBox(self)
  
        # setting geometry of combo box
        self.combo_box.setGeometry(200, 150, 120, 30)
  
        # geek list
        geek_list = ["Geek", "Geeky Geek", "Legend Geek", "Ultra Legend Geek"]
  
        # adding list of items to combo box
        self.combo_box.addItems(geek_list)
  
        # setting roles to the items
        self.combo_box.setItemData(0, "First role")
        self.combo_box.setItemData(1, "Second role")
        self.combo_box.setItemData(2, "Third role")
        self.combo_box.setItemData(3, "Forth role")
  
        # create push button
        button = QPushButton("Show", self)
  
        # adding action to the button
        button.pressed.connect(self.show_role)
  
        # creating label
        self.label = QLabel(self)
  
        # setting geometry of the label
        self.label.setGeometry(200, 200, 200, 30)
  
    def show_role(self):
  
        # getting the role of selected item
        role = self.combo_box.currentData()
  
        # showing the role throw label
        self.label.setText(role)
  
# create pyqt5 app
App = QApplication(sys.argv)
  
# create the instance of our Window
window = Window()
  
# start the app
sys.exit(App.exec())