I have a class that performs analyses and attaches the results, which are pandas dataframes, as object attributes:
>>> print(test.image.locate_DF)
Maybe the problem has been solved.
Emmm, but I still want to add some comments.
I save the pkl file on the server, but when I load it on my MAC, it crashed, showing 'Dataframe' object has no attribute '_data'
Finally, I found that pandas on my Mac is 1.0.5 but 1.1.5 on the server. When I updated it to the latest, it just worked.