[Pytorch] The problem and solution of the last batch data volume is less than batch_size

If the total amount of data cannot be divisible by batch_size, there will be a problem that the data volume of the last batch is smaller than batch_size. The solution is as follows:

Method 1 Drop the last batch and add drop_last = True
to the data loader parameters. Advantages : Save training time Disadvantages : When the batch_size is small, it will easily lead to increased loss

Method 2 Pack the last batch separately and still send it to training (Pytorch’s default method)
Advantages : Ensure training integrity
Disadvantages : Increase training time