code: def resize_preview(self, dw, dh):
          "Resizes preview that is currently dragged"
  
          # identify preview
          if self._objects_moving:
              id_ = self._objects_moving[0]
              tags = self.canvas.gettags(id_)
              for tag in tags:
                  if tag.startswith('preview_'):
                      _, ident = tag.split('preview_')
                      preview = self.previews[ident]
                      preview.resize_by(dw, dh)
                      self.move_previews()
                      break
          self._update_cregion(f resize_preview(self, dw, dh):
          "Resizes preview that is currently dragged"
  
          # identify preview
          if self._objects_moving:
              id_ = self._objects_moving[0]
              tags = self.canvas.gettags(id_)
              for tag in tags:
                  if tag.startswith('preview_'):
                      _, ident = tag.split('preview_')
                      preview = self.previews[ident]
                      preview.resize_by(dw, dh)
                      self.move_previews()
                      break
          self._update_cregion()
docs: Resizes preview that is currently dragged