When iterater over one huge data file, how to load next huge data file?

[asr-pub]

Hello, I have ten python pickle files, such 1.pkl ~ 10.pkl, every pickle file larger than 10GB,
whth the RAM limited, How can I:

Epoch start
    Load 1.pkl in dataset，training complete, then
    Load 2.pkl in dataset, continue training
    ...
    Load 10.pkl in dataset, continue training
Epoch end

How can I achieve this in PTL ? Thank you