doubt in DataListLoader

[steffyalbert]

I am using a custom dataset of fluid simulation and I am using the dataloader as follows:

Using a custom collate function as above, but I am getting the error as

How can resolve this TypeError: can only concatenate list (not "Data") to list?

[rusty1s]

What shall `l = sum(items, []) be doing? In order for the call to succeed, it needs to be passed a list of lists. Otherwise:

def collate(items):
    return Batch.from_data_list(items)

should work just fine (and is equivalent to loading via DataLoader).