def flags(self, index):
     flags = VariableListModel.flags(self, index)
     if index.isValid():
         flags |= Qt.ItemIsDragEnabled
     else:
         flags |= Qt.ItemIsDropEnabled
     return flags
 def flags(self, index):
     flags = VariableListModel.flags(self, index)
     if index.isValid():
         flags |= Qt.ItemIsDragEnabled
     else:
         flags |= Qt.ItemIsDropEnabled
     return flags