code: def populate_combo_box(self):
          
          if self.radio_button_production.isChecked():
              self.source = production_api['url']
              available_data = production_api['available_data']
  
          else:
              self.source = development_api['url']
              available_data = development_api['available_data']
  
          self.city_combo_box.clear()
          for index, data in enumerate(available_data):
              self.city_combo_box.addItem(data['name'])
              self.city_combo_box.setItemData(
                  index, data['code'], Qt.UserRole)
docs: Populate combobox for selecting city.