@SimonW or the sake of sanity check, is:
len(dataloader) = dataset size / batch size

?
I am getting these values as I print which are confusing me:
len(dataloaders['train'].dataset)=236436
len(dataloaders['train'])=59109
len(dataloaders['train'])/opts.batch_size=14777.25

related: How can I know the size of data_loader when i use: torchvision.datasets.ImageFolder 21