code: def load_annot(self):
          
          if self.parent.info.filename is not None:
              filename = splitext(self.parent.info.filename)[0] + '_scores.xml'
          else:
              filename = None
  
          filename, _ = QFileDialog.getOpenFileName(self, 'Load annotation file',
                                                    filename,
                                                    'Annotation File (*.xml)')
  
          if filename == '':
              return
  
          try:
              self.update_notes(filename, False)
          except FileNotFoundError:
              msg = 'Annotation file not found'
              self.parent.statusBar().showMessage(msg)
              lg.info(msg)
docs: Action: load a file for annotations.